That's 6,000 billion dollars. This sum, together with the current PayRoll tax revenues is enough to keep Social Security and Medicare in the black for years to come. Without the vast sum wasted on the war on terror, Republicans would not have an excuse to be trying to cut Social Security and Medicare for budget reasons and to privatize the old age pensions and health care of people, thus turning Medicare and Social Security pensions into fee income for Wall Street.

Combatting terrorism is the excuse for squandering a minimum of $6,000 billion dollars.
What were the terrorist events that serve as a basis for this expenditure?

There are five: 9/11, the London transport system bombings, the Spanish train bombing, the Boston Marathon Bombing, and the French Charlie Hebdo rifle attack.

In other words, 5 events in 14 years.