A.) Poison Gas is the answer
With the exception of Austria-Hungary, new imperialism was entrenched in the policies of all the European powers. This frenzy to acquire colonies was due to the potential financial and psychological benefits that colonies provide. Financially speaking, the colonies can help European nation’s name economy by firstly providing the raw materials necessary for industrialization which were lacking in continental Europe. Secondly, after using the raw materials to produce the merchandise, the colonies provided a market where the European nations can sell their manufactured goods. Hence, new colonies can begin an exploitive cycle where the European nations take resources from their colonial subjects then profits exportation of completed goods
The past war crash in america occured after WW1 as the result of high inventories of manufactored goods with no local buyers and a drop-off in exports, and falling prices for farm produce
Missiles. Soviets developed ICBM could reach U.S. and carried nuclear weapons, space, CIA used U-2 aircraft that flew so high they couldn't be shot down but was shot down in 1960.
