The number of American military personnel began to increase significantly after the attacks on September 11, 2001, as the United States began military operations in Afghanistan and Iraq. The number of troops deployed to these countries reached a peak in 2007, with over 170,000 troops in Iraq and over 50,000 troops in Afghanistan. Since then, the number of troops has steadily declined, with the last American combat troops leaving Iraq in 2011 and Afghanistan in 2014. However, the United States still maintains a significant military presence in both countries, with several thousand troops still deployed to each country.