This started as an uprising against shortages and mounting deaths in the war in 1917 in Russia. Nicholas facing mutinies abdicated the throne and a provisional government was established which brought a struggle for power and instability in the government. This was important because it allowed Lenin to step in and head the radical Bolshevik Party that would exit the War and completely turn Russian society around.
The Bolshevik rulers were able to end Russia's involvement in WWI when they signed this with Germany. It's important because it gave the Germans possession/control of a lot of Russian territory and 1/3 of it's population and the terms were harsh and humiliating but it gave the Russian government a chance to deal with their internal problems.
This settlement in Paris was dominated by Britain, France, and the US but included 27 nations all having conflicting goals and the leaders of the Central Powers or Soviet Union were not included. It was important because it was here that Woodrow Wilson introduced his 14 points but no one really listened to them and instead what happened was the Central Powers had to accept guilt and pay reparations for the cost of war. Austria and Hungary were also separated and reduced with the new states being added to eastern Europe. It was important because the peace settlement just made everyone bitter and would also bankrupt a lot of the nations involved.
The league of nations was created to maintain world peace and included 42 nations. It was important because it was theoretically a great idea but had no real power to solve international disputes or enforce decisions and in order to ensure collective security it needed all major powers and the US never joined.
This global conflict began with Japans invasion of Manchuria in 1931 which drew criticism from the League of Nations at which point Japan withdrew from the League and launched a full-scale invasion of China. This was important because of the way that they invaded, known as the "Rape of Nanjing" they waged war against civilians--bombings, rape, slaughter. This was important because of the devastating affects it had on the Chinese population and because the treatment of the Chinese by the Japanese brought them together and increased nationalist and communist ideals.
Germany's invasion of Poland during World War II was important because it showed that the policy of appeasement was not going to work out causing Britain and France to guarantee the security of Poland. Then Germany made a treaty with the Soviet Union that said they wouldn't attack each other and a secret protocol that divided eastern Europe into German and Soviet spheres of influence (German control of western Poland and Soviet Union in eastern Poland)
Germany wanted to invade the Soviet Union because from their they could expel/exterminate the Jews, Slaves, and Bolsheviks and create more "living space" for resettled Germans, Hitler believed this would be easy because of their financial problems. They were able to capture the Russian heartland, put Leningrad under siege, and have troops outside of Moscow but Germany had underestimated the Russian troops. They had a lot more people than they realized, a better industrial capacity and the Russian winter was hard for the ill-prepared German troops. Although this did stall the troops in the spring the German forces regrouped and inflicted heavy loses to the Soviet forces. This was important because it brought the Soviet Unions much needed force for the Allies and allowed for German defeat at Stalingrad.
Because of German forces had lost much of their momentum the Soviets were able to regroup and take back territory. The battle of Stalingrad was important because it was the 1st large-scale victory for Soviet forces and they were able to effectively push the German invaders out of Russian territory.
British and US troops land on French coast of Normandy, the fighting was deadly on all sides but the Germans were overwhelmed having both fronts collapsing around them and round-the-clock strategic bombing by the US and Britain invading/bombing German cities. Important because it brought the unconditional surrender of Germany in 1945.
A brutal street-by-street battle in order to capture Berlin. Important because it gave Berlin to the Soviets.
This was a supranational organization dedicated to keeping world peace and security and was met with cooperation with the Allies during the war. It was important because it succeeded in areas where the League of Nations had failed--they created a powerful security council responsible for maintaining international peace, they also made certain that the Security Council consists of 5 permanent members and 6 rotating elected members. (The US, the Soviet Union, Great Britain, France, China) And the decisions of the Council are binding on all members.
Unable to solve conflict between Arab-Palestinians and Jewish settles the Britain turned to the UN who proposed dividing the two states (Palestine and Israel), Arabs opposed the idea. In 1947 when Britain withdrew a civil war broke out and the Jews proclaimed the state of Israel which caused Egypt, Jordan, Syria, and Iraq to declare war on them. This was important because when Israel achieved victory they took more land than was originally given to them and the dispute over land has caused problems ever since.
This conflict was between Arab Palestinians and Jewish settles. The Arab Palestinians were violently resisting British rule and Jewish settlement, Egyptian military leaders under Gamal Abdel Nasser opposed Israel and wanted to take command of the Arab world. Nassar became prime minister and leader of pan-Arab nationalism, this put Egypt--basically just a mess
This conflict began with North Korea's (communist) invasion of South Korea and came to involve the United Nations (mostly led by the US) allying with South Korea and People's Republic of China allying with North Korea. Important because although it ended in a stalemate the division of Korea.
The war began under the command of the Front de Liberation Nationale, a group of nationalists, and used guerilla warfare to get the French out of Algeria. At first France did not realize the seriousness of the Algerian forces but when they sent thousands of forces. By 1958 they had sent 1/2-million soldiers resulting in atrocities on both sides and heavy civilian casualties. This was important because although it did also bring about Algerian Independence hundreds of thousands had died and a new ideological legacy stemmed from it--the work of Frantz Fanon. His writings gave support for African nationalism and revolutions and influenced independence struggles throughout Africa.
France had lost power in Vietnam when Japan invaded but reasserted colonial rule in 1945, Ho Chi Minh and followers were able to defeat them using guerrilla warfare and getting help from Communist China. This was important because in order to achieve peace they had to have a conference where Vietnam was divided (North and South) at the 17th parallel.
In 1953 the CIA helped bring anticommunist Shah Mohammed Pahlavi gain power. His repressive rule was overthrown by Islamist followers of Ayatollah Khomeini who also attacked the US for supporting the shah. The revolution had a strong anti-US presence and they took sixty-nine American hostages for 444 days, shut US military bases, and confiscated US-owned economic ventures. This was important because it shows the power of Islam as a means of fighting off foreign influences and the influence Iran's actions had on other Muslims to take terrorist action.
The Iraqi president Saddam Hussein launched an attack on Iran hoping for a quick victory it started out successfully but faced determined Iranian forces and the war dragged on until 1988. Important because of the amount of soldiers killed and the destruction it has brought to both countries.
The Soviets had been fighting long and hard against the Islamic warriors in Afghanistan who were being supported by Saudi Arabia, Iran, the US, Pakistan, and China. Finally in 1986 the Kremlin decided to pull its troops out of the war because it cost too much, had little support, and wasn't likely to be won. This was important because the Taliban emerged out of the disorder and devastation of the Afghan-Soviet war and the later civil war in Afghanistan.
This was a conflict between Iraq and a group of countries led by the US to remove Iraqi forces from Kuwait which they had invaded to control their oil supply. The war ended when the US crushed Iraqi resistance and liberated Kuwait. Important because it was a bit of a one-sided war and brought about continued conflict with Iraq.
When industrial and agricultural production continued to go down with increasing inflation the Soviet economy suffered dramatically. This led to many of the Baltic peoples wanting to secede and ultimately declare their independence. Soviet Leaders would either threaten to repress their uprisings or promise better conditions but neither stopped the move towards independence. Led by Boris Yeltsin a group of conspirators decided to take power while Gorbachev was on vacation. Yeltsin dismantled Communist party and led market oriented economic reforms. This was important because it ended the Soviet Union.