At the end of World War I, due to mounting war debts, the recently established Income Tax was drastically increased from a top marginal rate of 15% in 1916 to over 75% in 1918. After the war ended, the Government drew down the military and eventually changed its policy towards income tax, bringing it back down into the 20s.
During 9/11 George W Bush was president of the United States. He increased intervention by starting the war on terror.
North America was the closest comparison. The mongol empire covered 9.15 million square miles of land while North America covers 9.54 million square miles of land.
