As such, comparative advantage is an important concept in global trade, and it's the reason many countries concentrate on trying to produce certain goods or services more efficiently than other countries.
In March 2013, the total cost of the Iraq War to date was estimated at $1.7 trillion by the Watson Institute of International Studies at Brown University. Some argue that the total cost of the war to the U.S. economy will range from $3 trillion to $6 trillion, including interest rates, by 2053, as described in the Watson Institute's report.
In total, these wars are costing the government $40 billion a year to compensate veterans and survivors. World War I still costs taxpayers $20 million a year, World War II $5 billion and the Korean War $2.8 billion. The total cost of the Vietnam War, estimated to be more than $1 trillion in current dollars, includes $270 billion paid out in benefits.