When President Barack Obama cited cost as a reason to bring troops home from Afghanistan, he referred to a $1 trillion price tag for America's wars. Staggering as it is, that figure grossly underestimates the total cost of wars in Iraq, Afghanistan and Pakistan to the U.S. Treasury and ignores more imposing costs yet to come, according to a study released Wednesday. The final bill will reach at least $3.7 trillion and could be as high as $4.4 trillion, according to the research project "Costs of War" by Brown University's Watson Institute for International Studies. In the 10 years since...