martes, 30 de agosto de 2011

World War II

Concept. Twenty years after completing the first world war, the conflict was unleashed that has suffered more devastating humanity: The Second World War (1939-1945. About 40 million dead and many injured, disabled and orphans, whole cities, fields , roads, industrial centers, historical monuments were destroyed. All this was the fastest product of scientific and technological development to exterminate the enemy, to destroy human beings. Causes.
     
Mediate causes.
  
* The ideological divide between Nazi fascism in Germany and Italy and the Western democracies.
While the political and legal foundations of Western countries proclaimed and practiced the exercise of political and religious freedoms of its citizens, the Nazi-Fascist regimes of Germany, Italy, Japan proclaimed the supremacy of state over the citizen.
  
* The desire of the Soviet Union to spread its communist ideology and regain the territories lost in 1917.
  
* The aggressive and militaristic Germany, Italy and Japan. Hitler annexed Austria in 1938, after the Austrian Nazi party, prepare the way and German troops occupied the country without resistance.
This annexation was ratified by a plebiscite of the Austrian people. * The enmity between the U.S.
and Japan for their neo-colonial ambitions in the Pacific and the Far East.


  
Immediate causes.
* The non-aggression pact between Germany and the Soviet Union, which occurred on August 23, 1939 shocked the world, as two opposing ideological powers and enemies agreed to refrain from war and anti-integration blocks one or another nation. * The attack German to Polish Dantzg corridor (which separated the German territory into two parts), the war began September 1, 1939.
UK and France were without support from the powerful Russian and Germany free to continue its territorial expansion. Origen. Unlike what happens with the first world war, historians disagree on the issue of the responsibilities of the Second World War. This is attributed to Hitler, the Nazi füher who dragged his country into the adventure fueling his desire for revenge against the victors of 1948 and against the treaty of Versailles, claiming the need for German expansion and extolling the superiority of the Germanic race on all the other ethnic groups: Jews, slaves, Africans .... In late November 1937, Hitler believed that Germany was sufficient bonusstars armed and well-directed by the Nazi Party to undertake the conquest of living space needed by the German nation and deal with a war against democracy, that is, against France and Britain, which opposed his annexations in Central and Eastern Europe and all forms of remuneration colonies. The German alliance with Mussolini and Fascist Italy held on the occasion of the recent Spanish Civil War seemed to assure the Rome-Berlin axis an overwhelming superiority over Paris and London. In the early summer of 1939, negotiations began in Moscow in this regard when, against all expectations, the news broke that Hitler and Stalin just concluded a deal that aligned to the birthplace of consumerism in the field of totalitarian dictatorships. Germany and Russia agreed to a new unit in Poland. France and Britain announced they would oppose it with weapons. DEVELOPMENT OF THE SECOND WORLD Gurr Japan in the Pacific Relations between United States and Japan continued to deteriorate. De1940 In September, Japan forced the French government to give northern Indochina. U.S. responded to this action by banning the export of steel and fuel to the Japanese. When Germany invaded the USSR in June, Japanese leaders thought about joining the offensive from the east, but eventually chose to occupy southern Indochina. U.S., UK and the Netherlands froze Japanese assets to prevent Japan could buy oil, which eventually completely cripple its navy and its air force. Japan, the apparent imminence of the Soviet defeat in the summer and autumn of 1941 saw a great opportunity to seize oil and other resources of Southeast Asia and the surrounding islands, but I knew that these actions would unleash a war against the United. UU. The U.S. government wanted to stop Japanese expansion but was not sure that public opinion was prepared to go to war to achieve this goal. Harassed by the oil embargo in mourning, the Japanese decided to launch an attack on Southeast Asia.

  
The Japanese army and navy had developed a strategy based on making quick attacks to some islands to establish a defensive belt in the central Pacific. U.S. expected
they declare war, but did not believe they were willing to prolong the war for a long time. Japanese forces had conquered the British possessions as well as some Americans. The British colony of Singapore, long regarded as one of the most impregnable fortresses in the world, fell in February 1942, the Japanese also occupied Dutch East Indies and landed in New Guinea. It had been so successful the campaign, they decided to expand its defensive perimeter. The Americans, who could decipher the coded messages of the Japanese, they placed a naval expeditionary force in this area.
After the Battle of the Coral Sea the Japanese were forced to abandon the plans Germany invades the Soviet Union On the morning of June 22, 1941, more than 3 million German soldiers began the invasion of the USSR. The Soviet Army had 2.9 million soldiers on the western border and was 2 times higher than the German tanks and aircraft 10 times. Many of their tanks were outdated, but others were much more sophisticated than the Germans. The Germans had organized three groups of armies for the invasion, called North, Central and South, heading toward Leningrad, Moscow and Kiev. Hitler and his generals had come to the conclusion that its main strategic problem was to block the Soviet army during the battle and defeat him before he could escape deep into the country, however, disagreed on how to overcome this disadvantage. Most of the generals believed that the Soviet regime would sacrifice everything to save Moscow, the capital, the junction of rail and road networks, and the main industrial center of the USSR. According to Hitler, land and resources of Ukraine and the Caucasus oil were more important. The Russians acted, as envisaged by the German general, sacrificing huge amounts of troops and weapons to defend Moscow. However, Hitler was not satisfied and, despite the protests of his high command, the army group command center directing the armored forces to the north and the south to help the other 2 armies, which halted the advance Moscow. Launched a strong counter Stallin the Russian reserve forces on December 6 and after a few days, the group of German advance was hit. Hitler ordered his troops to stand firm in the positions they were found, which managed to maintain the siege on Leningrad, Moscow and keep continue stalking the western Ukraine. THE U.R.S.S Acronyms Union of Soviet Socialist Republics, federal state located in the N. Eurasian block. Emerged in the 1979 socialist revolution, has contributed an industrial economy characterized by high growth that has placed among the top world in which a heavy production is concerned. The First Congress of Soviets, held on December 30, 1922, community decided the constitution of the Union Soviet Socialist Republic (USSR), comprising Russia, Ukraine, Belarus, Transcaucasia and Central Asia republics. The German invasion surprised the USSR and the first months of the blitz launched by the Germans were catastrophic. But the Red Army, although inferior in arms, managed to dominate Hitler's troops at the gates of Moscow and Leningrad, neutralized the advantage in February 1943, asserted its superiority and eventually beat the Wchrmacht, who left the Soviet territory in the summer of 1944. This year, relations between the USSR and the Western Allies improved. In February 1945 in Yalta in July and August in Postclam, the Allies recognized a zone of Soviet influence in that part of Europe liberated by the Soviet army. But in the years following the establishment of popular democracy in Central Europe alarmed the West and caused the onset of the Cold War.

   
The atomic bomb Throughout the conflict, U.S. government and Britain had done a great scientific and industrial project for the development of nuclear weapons, and believed that Germany was being investigated in the same field. There was a lack of sufficient amounts of major elements, uranium and plutonium fissile before the end of the war in Europe.
The first atomic bomb was exploded in a test conducted on July 16, 1945 alamogardo (New Mexico, USA). 2 bombs had been manufactured more, and began to consider the possibility of using them against Japan to get his surrender. U.S. President Harry S. Truman allowed to launch these 2 devices because, he explained, believed they could save thousands of lives, the first fell on Hiroshima on August 16th, which destroys the three-quarters of the buildings and kill the ¼ of the population, and the second was dropped on Nagasaki three days later. Estimates of U.S. indicate that between 66,000 and 78,000 died at Hiroshima and that the number of victims in Nagasaki was 39,000.
the Japanese claim that low amounted to a total of 240,000 people. Peace Agreement The conference of Yalta: The Allied leaders had held several interviews on the war and to agree on peace. Thus, in February 1945 met U.S. President Roosevelt, British Prime Minister Churchill and Soviet Premier Stalin in the Russian city of Yalta. They issued the so-called Yalta Declaration, which expressed their intention to destroy German militarism and Nazism and to ensure that Germany does not disturb the peace of the world has ever, in addition to subject all war criminals to justice and swift punishment and exact reparation for the destruction caused by the Germans. It approved the decision to decide Germany into occupation zones that would be administered through a central control commission based in Berlin and it was agreed to invite France to take over management of the zones of occupation and to participate in the commission control. It was decided to establish a commission of war reparations that would operate in Moscow. It also reported that in April would be held in San Francisco for the founding conference of the United Nations organization. On April 25, 1945, the Conference of San Francisco created the United Nations (UN), whose charter was enacted by June. However, it took 18 months of negotiations for the February 10, 1947 were signed at Paris peace treaties between the United nations, Finland, Hungary, Romania, Italy and Bulgaria. As regards Japan was demilitarized and occupied by U.S. The text of the treaty of Yalta was made public in 1947. objectives of this meeting, aimed at the result of the Pacific cocristencia once the war ended by dividing spheres of influence, failed to be effective when the same decision originated the Cold War, partly motivated by the formation of blocks led the principles enshrined in Yalta. The Potsdam conference: After the war with Germany, met Stallin, President Truman and the English prime minister Clement Attlee in the German city of Potsdam. It was discussed and agreed how totally overcome Japan and the restructuring of Europe. As a result of these agreements the vanquished lost territories: * Germany was reduced and divided into four occupation zones between Americans, British, French and Russians. * Italy lost part of their territory boundary and all its colonies. * Japan was stripped of all conquered during the war and of Manchuria and Korea. Some of its islands were scrubbing the Soviet Union. There were small changes in boundaries and volcanic core nations. The most beneficial of the winner was the Soviet Union, which won recognition from the Baltic countries occupied part of Romania and eastern Poland, which in turn obtained regions of Germany. Germany was then divided in 1949 by the victors of the war, the western areas came together to form a federal republic and the contractor by the Soviets, became a communist state. Berlin, the former capital, was itself divided into East Berlin and West Berlin but was located within Soviet territory. 1946 the government of the eastern began building a wall to separate the 2 halves of the city. The Berlin Wall went on to make a symbol of what the cold war would be known as the Iron Curtain

  
The Axis powers Hitler (the great responsible for the second world war), I knew perfectly well that his confrontation with the Soviet Union would be inevitable. The struggle to overcome the limitations of ideology between Nazism and communism. The Fuhrer believed the conquest of the USSR with a historic mission whose end would be to submit this and acquire slaves living space for Aryans (dominant race and higher). For convenience in 1939, Germany signed a nonaggression treaty with the USSR. At that time project invade Poland and the adoption of such a fact would mean that France and Britain, it was desirable that Russia will join.
The non-aggression pact committed the two nations not to deal in war and included a secret agreement in which the USSR would extend his dominions by Eastern Poland, Finland, Latvia, Estonia and the Romanian provinces. As Germany invaded western Poland, Denmark, Norway, Holland and France, the Soviet dictator, Joseph Stalin, lost no time in claiming their share of the spoils. Between September 1939 and June 1940, the Red Army seized eastern Poland, occupied the Baltic states, including Lithuania, assigned to the Germans, and book a short winter war with Finland. In June, Stalin annexed Bessarabia and Northern Bukovina, the two Romanian provinces. Hitler, concerned about the aggressiveness of the USSR, created a protectorate over the rest of Romania and concluded several agreements with Finland in the summer and autumn of 1940. The September 27 agreement signed on Spindle although the deal was clearly aimed at U.S. and explicitly rule out the meeting with the USSR, Stalin began to panic. The Soviet Foreign Minister Molotov Vyacheslavi however called for more concessions, Hitler refused and negotiations broke down. A few months after Russia signed a neutrality pact with Japan. Thus, the USSR clearly protected its eastern flank in anticipation of a possible clash with Germany, that would allow him to arrange his forces in a single front. At 3 am on June 22, 1941, Germany launched the most ambitious military offensive of all time. Along a front of 3,000,000 million km 1800 of the Third Reich soldiers penetrated into Eastern Europe in the direction of Leningrad, Moscow and the Caucasus. They overcame every obstacle with ease hastily put the USSR in its path and moved with surprising ease. On October 20 German tanks were at 64 km from Moscow. Apparently Hitler was going to add another resounding victory for his sweeping series of successes. This time, however, his star was eclipsed. The Russians had formidable reserves of men and resources and made use of them: consolidated their positions, reorganized his troops and increased their production of weapons. In the winter of 1942-1943 went on the counterattack, annihilated the German Sixth Army Stanligrado and forced the invaders to start the withdrawal. Stanligrado, the first major defeat of Hitler's army from the beginning of the war marked a turning point in the course of events.
Since then, though the war lasted for over 2 years and many battles were fought, the Germans never regained its former pulses and vigorous and brilliant victories. The Allies U.S. finally the three companies and it deployed all their resources, many hundreds of millions of dollars, more than 16 million soldiers, 300,000 planes, 85,000 tanks and a fleet of more than 20 million tons. The Americans not only created a powerful arsenal of its own but also provided assistance to the United Kingdom, the USSR, China, and other allied countries. At the same time will fight on two fronts: Europe and the Pacific. Americans before intervening in the conflict had already cooperated actively arming of allies. On the eve of the German invasion of Poland in September 1939, President Roosevelt ask Congress the revision of the Neutrality Act, prohibiting the sale of U.S. arms to belligerents. 2 months later, the law allowed England and France to buy arms in the country, but had to pay cash and provide the means of transport. The lightning attack by the Nazis on why France and the Netherlands further concessions, USA increase the sale of arms and took care of the repair of ships in the UK and the training of British pilots of the RAF. By 1941 Congress passed more concessions and opened a channel of credit to countries at war against the shaft. In January 1941 U.S. and Britain signed a treaty whereby if the Yankees entered the war would be top priority to defeat the Germans first and then deal with Japan. Immediately after the official break of hostilities, USA Britain reaffirmed its decision to go mainly to Germany. By September 11 the Allies were already in much of Africa and rapidly advancing east on the north coast of Africa, soon the Allied advance was stopped by the winter rains to the west and Bizerte, and in December the Axis forces began violent counterattacks. The inexperienced American troops first clashed with the German veterans and suffered a severe defeat in February 1943. In early May, the Allies began their final assault on Tunis and 13 soldiers of the same month 275 000 125 000 of them German axis disposed arms. The North African possession charge to 275.000 victims and allies of the Axis forces lost a significantly greater number of soldiers. In January 1943 was held in Casablanca conference of allied nations. In it, U.S. and the UK showed their disagreement over the strategy that should follow once the operation in Africa. U.S. General George Marchall was in favor of invading France that same year, but Churchill favored a campaign against Italy, it was said, the area most vulnerable in Europe. "Allied naval forces under the command of General Eisenhower and supported by strong air contingent, began this morning the troops landed on the shores of France." This statement from the Supreme Headquarters Allied Expeditionary Force (Shafer, for its acronym in English) is day to meet the June 6, 1944, exactly 4 years and 2 days after the last Dunkerwque evacuated British troops to escape of fulminant Nazi offensive in 1940. the night before, the most powerful amphibious force of history lay before the coast of Normandy, and at dawn, more than 150,000 troops, the Sivers distribution divisions began landing on the beaches Utah, Omaha, Gold, Juno and Sword. In other issues, however, the Allies reached an agreement. It created a council of foreign ministers to prepare peace treaties with Italy, Romania, Finland, Hungary and Bulgaria. Germany was decided to remove all vestiges of Nazism and militarism, and form an international tribunal to try Nazi leaders for crimes committed while exercising the power. Also provided that all Germans living in Hungary, Czechoslovakia and Poland were shipped to Germany as soon as possible. But the importance of these issues was only relative. Major problems remain unresolved or were ignored

Dia De La Independencia Colombia

Ya en 1809 se habían producido los primeros gritos de libertad en la América española, en lo que hoy es Ecuador y Bolivia. En la Nueva Granada se habían gestado de manera similar, y ciudades como Cartagena y Mompos habían conformado juntas independentistas que buscaban mayor autonomía e incluso una independencia absoluta de España
En la provincia de Santa fe se había creado una junta de notables integrada por autoridades civiles e intelectuales criollos. Los principales personeros de la oligarquía criolla que conformaban la junta eran: José Miguel Pey, Camilo Torres, Acevedo Gómez, Joaquín Camacho, Jorge Tadeo Lozano, Antonio Morales, entre otros.
Estos comenzaron a realizar reuniones sucesivas en las casas de los integrantes y luego en el observatorio astronómico, cuyo director era Francisco José de Caldas. En estas reuniones empezaron a pensar en la táctica política que consistía en provocar una limitada y transitoria perturbación del orden público y así aprovechar para tomar el poder.
La junta de notables propuso entonces crear un incidente con los españoles, a fin de crear una situación conflictiva que diera salida al descontento potencial que existía en Santafé contra la audiencia española. Lo importante era conseguir que el Virrey, presionado por la perturbación del orden, constituyera ese mismo día la Junta Suprema de Gobierno integrada por los regidores del Cabildo de Santafé.
Don Antonio Morales manifestó que el incidente podía provocarse con el comerciante peninsular don José González Llorente y se ofreció "gustoso" a intervenir en el altercado. Los notables criollos aceptaron la propuesta y decidieron ejecutar el proyecto el viernes, 20 de julio, fecha en que la Plaza Mayor estaría colmada de gente de todas las clases sociales, por ser el día habitual de mercado.
Se convino que un grupo de criollos (encabezados por Pantaleón Santamaría y los hermanos Morales) fueran el día indicado a la tienda de Llorente a pedirle prestado un florero o cualquier clase de adorno que les sirviera para decorar la mesa de un anunciado banquete en honor a otro criollo destacado, Antonio Villavicencio. En el caso de una negativa, los hermanos Morales procederían a agredir al español.
A fin de garantizar el éxito del plan, si Llorente entregaba el florero o se negaba de manera cortés, se acordó que don Francisco José de Caldas pasara a la misma hora por frente del almacén de Llorente y le saludara, lo cuál daría oportunidad a Morales para reprenderlo por dirigir la palabra a un "chapetón" enemigo de los americanos y dar así comienzo al incidente.
Según cuentan algunos testigos, los criollos fueron al almacén de Llorente a pedirle prestada una pieza. Algunos dicen que fue un ramillete, otros un farol y otros un florero, con el fin de adornar la mesa de Antonio Villavicencio. Llorente se resiste porque dice que la pieza está maltratada y en mal estado. Se arma el tumulto y se convoca a un cabildo abierto poniéndose en sintonía con lo que ocurre en las otras provincias de la Nueva Granada y lo que ocurre en las otras colonias españolas", cuenta Daniel Castro, director del Museo de la Independencia, lugar donde ocurrieron los hechos del 20 de julio y donde aún reposa una parte de la pieza que los criollos fueron a pedir prestada.
Poco antes de las doce del día, como estaba previsto, se presentaron los criollos ante Llorente y después de hablarle del anunciado banquete a Villavicencio, se le pidió prestado la pieza para adornar la mesa. Llorente se negó, pero su negativa no fue dada en términos despectivos o groseros. Se limitó a explicar diciendo que la había prestado varias veces y ésta se estaba maltratando y por lo tanto, perdiendo su valor.
Entonces intervino Caldas, quien pasó por frente del almacén y saludó a Llorente, lo que permitió a don Antonio Morales, como estaba acordado, tomar la iniciativa y formular duras críticas hacia Llorente. Morales y sus compañeros comenzaron entonces a gritar que el comerciante español había respondido con palabras contra Villavicencio y los americanos, afirmación que Llorente negó categóricamente.
Mientras tanto los principales conjurados se dispersaron por la plaza gritando: ¡Están insultando a los americanos! ¡Queremos Junta! ¡Viva el Cabildo! ¡Abajo el mal gobierno! ¡Mueran los bonapartistas! La ira se tomó el sentir del pueblo.

Cohete Funciona con hidrogeno

Luego de ver en la red algunos cohetes comerciales que funcionan con hidrógeno como combustible, decidí hacer uno más casero. Abajo se pude ver un cohete del tipo comercial.

El ignitor es un simple alambre de nicromo; el hidrógeno se consigue por electrólisi del agua en un tubo que luego se enciende por medio del alambre de nicromo. Pero en nuestro cohete la ingición será con una chispa de alto voltaje.
El cohete en si y todo los demás se hace con tubo de PVC y láminas de plástico. Para el cono es recomendable usar una punta suave (plastoform) para evitar accidentes.


Arriba se puede ver que se ha usado un circuito multiplicador de voltaje para poder obtener la chispa. Se lo puede obtener de una cámara fotográfica desechable que tenga flash. También se puede usar un ignitor tal como el que vemos en nuestro Catalogo . Este último es mucho más fácil de usar en el cohete.
El agua que se coloca en la base del cohete se separa en dus dos componentes principales (electrólisis) hidrógeneo y oxígeno, por medios de dos electrodos. Estos electrodos son simples barritas de carbón mineral obtenidos de pilas.


En el dibujo de arriba se puede ver el principio de funcionamiento del cohete con combustible de hidrógeno.

Arriba se puede ver la base donde se coloca el agua para la electrólisis y el circuito para hacer la chispa dentro del tubo.

Como se ve en la foto de arriba, el cohete tiene en su interior un émbolo que se introduc en el tubo del lanzador o base. Cuando se logra la electrólisis del agua, se acumula en el interior del tubo de lanzamiento hidrógeno y oxígeno. Al hacer saltar la chispa en estos gases se produce una especie de explosión que dispara al cohete a una altura considerable. En realidad no es un cohete porque no tiene propulsión propia, sino que se lo clasifica como un proyectil.

Primera Guerra Mundial









La Primera Guerra Mundial, también llamada la Guerra Mundial o la Gran Guerra hasta 1939, fue una guerra mundial centrada en Europa que comenzó el 28 de julio de 1914 y se libró hasta el 11 de noviembre de 1918. Involucró a todas las grandes potencias del mundo, que se alinearon en dos bandos opuestos: los Aliados de la Triple Entente y las Potencias Centrales de la Triple Alianza. En el transcurso del conflicto fueron movilizados más de 70 millones de militares, incluidos 60 millones de europeos,[2] lo que lo convierte en una de las mayores guerras de la Historia. Murieron más de 9 millones de combatientes,[3] muchos a causa de los avances tecnológicos de la industria armamentística, que hizo estragos contra una infantería que fue usada de forma masiva y temeraria.
El asesinato del archiduque Francisco Fernando de Austria, heredero del trono del Imperio austro-húngaro, el 28 de junio de 1914 en Sarajevo, fue el detonante inmediato de la guerra. Las causas subyacentes, como el imperialismo de las políticas exteriores de las grandes potencias europeas, incluidos el Imperio Alemán, el Imperio austro-húngaro, el Imperio Otomano, el Imperio Ruso, el Imperio Británico, Francia e Italia, jugaron un papel decisivo. El asesinato de Francisco Fernando por el nacionalista yugoslavo Gavrilo Princip dio como resultado un ultimátum de los Habsburgo al Reino de Serbia. Las potencias europeas invocaron diversas alianzas formadas años y décadas atrás, por lo que sólo unas semanas después del magnicidio las grandes potencias estaban en guerra. A través de sus colonias, el conflicto pronto prendió por el mundo.
El 28 de julio, el conflicto dio comienzo con la invasión de Serbia por Austria-Hungría, seguida de la invasión de Bélgica, Luxemburgo y Francia por el Imperio Alemán, y el ataque de Rusia contra Alemania. Tras el avance alemán en dirección a París se llegó a un alto, y el Frente Occidental se estabilizó en una guerra estática de desgaste basada en una extensa red de trincheras que apenas sufrió variaciones significativas hasta 1917. En el frente oriental, el ejército ruso luchó satisfactoriamente contra Austria-Hungría, pero fue obligado a retirarse por el ejército alemán. Se abrieron frentes adicionales tras la entrada en la guerra del Imperio Otomano en 1914, Italia y Bulgaria en 1915 y Rumanía en 1916. El Imperio ruso colapsó en 1917 debido a la Revolución de Octubre, tras lo que dejó la guerra. Después de una ofensiva alemana a lo largo del Frente Occidental en 1918, las fuerzas de los Estados Unidos entraron en las trincheras y los Aliados de la Triple Entente hicieron retroceder al ejército alemán en una serie de exitosas ofensivas. Tras la Revolución de Noviembre de 1918 que forzó la abdicación del Káiser, Alemania aceptó el armisticio el día 11 del mismo mes.
Al final de la guerra, cuatro potencias imperiales (los Imperios Alemán, Ruso, Austro-Húngaro y Otomano) habían sido derrotados militar y políticamente y desaparecieron. Los dos primeros, el alemán y el ruso, perdieron una gran cantidad de territorios, y los otros dos, el austro-húngaro y el otomano, fueron completamente disueltos. El mapa de Europa Central fue redibujado con nuevos y pequeños estados, y se creó la Sociedad de Naciones con la esperanza de prevenir otro conflicto similar. Los nacionalismos europeos espoleados por la guerra y la disolución de los imperios, las repercusiones de la derrota alemana y los problemas con el Tratado de Versalles se consideran generalmente como factores del comienzo de la Segunda Guerra Mundial.
En 1914, los europeos pensaban que la guerra sería corta. Pero los generales, que habían estudiado las guerras napoleónicas, estaban equivocados en su enfoque inicial del enfrentamiento, basado en el uso masivo de la infantería. Respondiendo a la enorme eficacia de las armas (fusiles, armas automáticas y artillería pesada), las fortificaciones fueron reforzadas. La caballería sería inútil como medio para romper el frente.
Al comienzo de la guerra los dos bandos trataron de obtener una victoria rápida mediante ofensivas fulminantes. Los franceses agruparon sus tropas en la frontera con Alemania, entre Nancy y Belfort, divididas en cinco ejércitos. Previendo un ataque frontal en Lorena, organizaron el Plan XVII. Los alemanes tenían un plan mucho más ambicioso. Contaban con la rapidez de un movimiento de contorno por Bélgica para sorprender a las tropas francesas y marchar hacia el este de París (Plan Schlieffen de 1905) y luego enfrentarse a las fuerzas enemigas y empujarlas hacia el Jura y Suiza. Tan sólo ubicaron 2/7 de sus tropas sobre la frontera para resistir el ataque frontal en Alsacia-Lorena.
El comienzo del plan trascurrió perfectamente para el Reich. Sus tropas avanzaron sobre Bélgica el 4 de agosto, lo cual provocó la intervención inglesa. Posteriormente derrotaron al ejército francés en diversas batallas. Los franceses lanzaron simultáneamente el Plan XVII, pero resultó un fracaso debido a las armas automáticas que frenaron cualquier asalto y a un repliegue prematuro de las tropas hacia sus líneas. Semanas después estaban ya ubicados en el río Marne, donde chocaron con el Cuerpo Británico y el ejército francés, quienes frenaron el avance alemán. La derrota germana frustró el plan original y acabó con las expectativas de una conflagración breve, marcando el abandono definitivo de los planes anteriores a la guerra. En ese momento comenzó la «carrera hacia el mar»: los dos Ejércitos marcharon hacia el Mar del Norte; ataques y contra-ataques se sucedieron. La contienda se desarrollaría en territorio francés y belga. Las tropas británicas no tardaron en intervenir en mayor número, junto a los restos del ejército belga.
Mientras tanto, Austria-Hungría fracasó en su intento de tomar Belgrado, lo cual lograría después con ayuda alemana, en agosto del 1915. Rusia invadió Prusia Oriental, pero los generales de estado mayor prusianos Hindenburg y Ludendorff los batirán contundentemente en Tannenberg.
En el curso de 1915, dos nuevos países entraron en la guerra: Italia del lado de los Aliados y Bulgaria al lado de las potencias centrales, que con este apoyo derrotan y ocupan a Serbia. Desde el comienzo de la guerra, el Vaticano y Suiza intentaron infructuosamente sondeos por la paz.