key interventions

With the West appearing ready to act against the Syrian government, here are 10 instances in which the United States has intervened, sometimes without U.N. authorization.

Grenada

Operation Urgent Fury: Unilateral U.S. military action. In October 1983, the United States led an invasion of Grenada, a Caribbean island nation, after a coup ousted the government of Prime Minister Maurice Bishop, who was assassinated. President Ronald Reagan was said to have been concerned about a 10,000-foot airstrip that the communist country's military was building and about the safety of 800 American medical students.

Panama

Operation Just Cause: Unilateral U.S. military action. In December 1989, the United States invaded Panama with more than 27,000 troops. Manuel Noriega, was overthrown in the operation, which lasted just over a month.

Iraq

Operation Desert Storm: U.N. authorized. After the army of Iraqi leader Saddam Hussein invaded Kuwait in August 1990, the U.N. Security Council imposed economic sanctions on Iraq. When the U.N. deadline for Iraq's withdrawal expired, the United States started an aerial war that drove Saddam Hussein's forces out of Kuwait. U.S.-led coalition forces advanced well into Iraqi territory.

Somalia

Operation Gothic Serpent: U.N. authorized. In June 1993, the U.N. passed a resolution declaring war on Mohamed Farah Aideed and his militia, after Aideed ordered an attack on a Pakistani force that was part of a U.N. operation. Starting in August 1993, U.S. troops attacked various targets in Mogadishu, the capital, to find Aideed. The operation ended in October, after a bloody overnight standoff later known as "Black Hawk Down," referring to the downing of two UH-60 helicopters by Aideed's men.

Afghanistan/Sudan

Operation Infinite Reach: Unilateral U.S. action. After the bombings of its embassies in Kenya and Tanzania, the United States in August 1998 launched cruise missiles at four terrorist training camps in Afghanistan in an attempt to assassinate Osama bin Laden and other Al-Qaida leaders. The United States also dropped missiles on a pharmaceutical factory in Sudan, claiming it was helping Bin Laden.

Federal Republic of Yugoslavia

Operation Allied Force: NATO operation not U.N. authorized. In March 1999, NATO began strategic airstrikes in Kosovo and Serbia because then-Yugoslav President Slobodan Milosevic was persecuting ethnic Albanians in Kosovo. After several weeks, Milosevic accepted a peace plan to end the fighting.

Afghanistan

Operation Enduring Freedom: NATO operation not authorized by the U. N. After the attacks of Sept. 11, 2001, the United States launched a war in Afghanistan, attacking Al-Qaida forces and the Taliban.

Iraq

Operation Iraqi Freedom: Unilateral U.S. military action. In March 2003, President George W. Bush announced a war against Iraq. U.S. forces launched airstrikes on Baghdad, then began a ground invasion of the city that quickly led to the collapse of Saddam Hussein's rule.

Pakistan, Yemen and Somalia

Unilateral U.S. drone strikes. Since 2002, the United States has regularly used armed Predator drones to target and kill terrorists in Pakistan, Yemen and Somalia.

Libya

Operation Odyssey Dawn: U.N. authorized. In March 2011, France and Britain led, with U.S. assistance, a military operation in Libya, conducting airstrikes against Libyan army installations and air-defense systems, and imposing a no-fly zone. The mission ended after Moammar Gadhafi's death in October 2011.

WASHINGTON POST