No. 4 With a Bullet

From Holden:

In inflation-adjusted dollars, the newspaper said, the war on terror ranks behind World War II, Vietnam and the Korean War. By the end of September the military cost of the war on terror, which began shortly after the Sept. 11, 2001, attacks with the invasion of Afghanistan, will top $250 billion. Costs for the Korea War totaled $361 billion, Yale University economist William Nordhaus told the Monitor.

Linda Bilmes, with the Kennedy School of government at Harvard University, told the newspaper she figured that if the war lasts another five years, the total bill will be about $1.4 trillion.