What have been the policy responses to combat Islamic terrorism? Please discuss both the United States' and others's policies (e.g., NATO, Russia, or the United Nations).

The war on Islamic terrorism is an American-led effort launched after the terrorist attacks of September 11, 2001. On that day, nineteen hijackers—fifteen from Saudi Arabia—killed nearly three thousand Americans. Other nations and NATO have participated in the effort to stop Islamic terrorism, but it is America who has led it from the outset.
The largest result of the conflict was the American invasion of Afghanistan in 2001 and Iraq in 2003. Al-Qaeda, which was blamed for 9/11, was based in Afghanistan. The rulers of Afghanistan, the Taliban, refused to hand Osama bin Laden to America after 9/11. In late 2001, the United States attacked and, assisted by the Northern Alliance, won an easy victory and overthrew the Taliban. However, the Taliban has continued to fight, and the war in Afghanistan has been a costly and perpetual stalemate. The second major American-led war was against Iraq. Saddam Hussein, however, had no role in the events of 9/11; the invasion actually exacerbated Islamic terrorism by unleashing sectarian violence. The two wars cost trillions of dollars and thousands of lives. These wars, especially the one in Iraq, also damaged America's image around the world.
America's reputation has also suffered because of its treatment of enemy prisoners: some were tortured by the Central Intelligence Agency, while other detainees have been held for many years without trial at Guantanamo Bay in Cuba.
America's allies assisted the war effort in both conflicts. NATO was active in Afghanistan, while Britain and some other nations sent troops to fight in Iraq.
The United States has also employed drones and small special forces units around the globe—especially in the Middle East. This small-scale strategy seems to be preferred now. The use of drones to kill suspected terrorists has been controversial, however.
The war on Islamic terrorism continues to this day. At present, it is being used as a justification for the build-up of American forces in the Middle East against Iran.