The reason that the Archdukewas assassinated was due to the Black Hand believing he was going to threaten Serbian independence, and ordered for him to be killed. He was ordered to be killed due to the fact he believed their forces weren't enough. This lead to his assassination because he believed Serbia deserved the territories of which the Archduke went to.
How could you kill the Archduke!?
He was threatening Serbian independence!
Someone sunk the Lusitania!
The lusitania sunk due to a German submarine/U-boat which shot a torpedo at it, which sank the Lusitania. It took the Lusitania only 18 minutes which some believe the torpedo shot the steam room, which allowed it to sink that fast. The Lusitania was sunk on May 7th, 1915.
Who could do such a thing?!
The Zimmermann Telegram was a message sent by Germany asking Mexico to go under an alliance with them, in exchange for attacking the US. Before it was sent to Mexico, Europe intercepted it, and notified the US of this. This led to the US entering into WWI, when they otherwise wouldn't of.
I intercepted a telegram from Germany, asking Mexico to rebel against the US!