Last week, after a decade of U.S. military presence in Afghanistan, President Obama announced a plan to begin withdrawing thousands of U.S. troops from the country this year. The war has been expensive -- a Brown University research project released Wednesday estimates the total cost of the U.S. wars in Afghanistan and Iraq at nearly $4 trillion (a figure that includes the ongoing cost of veterans' care). The human cost is more difficult to quantify, as more than 2,500 coalition troops (1,644 of them American) have now been killed, and civilian casualties are estimated at well over 100,000. Canadian combat operations in Afghanistan will end in July, as troops withdraw from the southern region and hand control over to U.S. forces. Just yesterday, a group of nine Taliban suicide attackers stormed a major hotel in Kabul that was popular with foreigners, killing 21 and raising fears of what may come as foreign troops depart the country. Some of the losing candidates in the September 2010 Afghanistan election, gather for a meeting organized for the disaffected losing contestants who have now been declared winners following a special investigative tribunal investigating alleged voting irregularities, in Kabul, Afghanistan, on Sunday June 26, 2011. There are 62 members of parliament who are alleged to have committed voting irregularities and fraud but who now refuse to leave parliament, creating an impasse for these candidates who are now unable to take their seat in the parliament. Foreign soldiers leave the Intercontinental Hotel at the end of a military operation against Taliban militants who had stormed the hotel in Kabul, on June 29, 2011. Taliban suicide bombers and gunmen attacked the Intercontinental Hotel in Kabul sparking a five-hour battle with Afghan commandos backed by a NATO helicopter gunship in an assault that left at least 10 people dead. Amy Balduf, of Richmond, Tennessee, is comforted by a Marine at the graveside of her husband, U.S. Marine Corps Sgt. Kevin Balduf, who was killed serving in Afghanistan, at Arlington National Cemetery, on Wednesday, June 15, 2011, in Arlington, Virginia.