They contributed to World War 1 through the assassination of Archduke Franz Ferdinand. The Black Hand was part of a Pan-Slavist movement in which they wanted to unite territories of South Slave that had been annexed by Austria-Hungry. Hopefully this helps.
Gorbachev pursued glasnost and perestroika reforms in part because the war in Afghanistan had drained the nation's resources. Mikhail Gorbachev, as known as the former General Secretary of the Soviet Union (Russia), noticed that there has been a huge decrease in their resources. They were fighting a war in Afghanistan, and used all of the nation's resources to help them win the war. Since they used most of their resources, they didn't have much to help the economy, so if they don't get enough resources back, the economy would fail. Because of this Gorbachev made a movement called "perestroika" to help get back the nation's resources. What this movement did was let the government speaker, or have a conversation, about the issues that are going on in the economy, and see if there could be a way to solve it.
The study of history allows us to learn from others mistakes, it allows us to make history while not making the same mistakes again.
I believe the most recent ice age ended nearly 11,700 years ago, but began nearly 2 million years ago.
