U.S.NATO countries work on plans for military action Syria after use of chemical weapons 2203131.

Seven months ago, President Barack Obama warned the use of chemical weapons in Syria could bring direct U.S. involvement in that country's raging civil war. While the administration's interest in U.S. military involvement in Syria remains low, planners still have been preparing for the possibility U.S. forces would have to step in and neutralize Syria's military or safeguard chemical weapons stockpiles.

Several NATO countries are working on contingency plans for military action in Syria, including imposing a no-fly zone, providing lethal military assistance to rebel groups and imposing an arms embargo on the Syrian government, Stavridis said. NATO hasn't discussed any such options as a whole, said NATO commander Adm. James Stavridis, on Tuesday, March 19, 2013.

NATO has installed Patriot missile batteries in Turkey, near its border with Syria, which could be aimed to shoot down Syrian aircraft, Stavridis said

But Turkey only allowed the missile batteries to be placed there for defensive purposes, and NATO nations would have to agree before they could be used for offensive strikes against Syria.

The U.S. military has enough airpower in the region to take action against Syria, according to officials. That includes fighter jets and bombers spread out across air bases in the Middle East and nearby aircraft carriers. The U.S. Navy also has warships equipped with Tomahawk missiles, which could be used to hit chemical weapons supplies.

But such strikes pose a danger of releasing chemical agents into the air around civilian populations in Syria, the officials said.

Other options include bombing runways to prevent Syrian aircraft from taking off, or disrupting communication between the regime leaders and ground commanders.

The United States has no plans to put "boots on the ground" in Syria. But the Pentagon is a planning machine, so the Defense Department last year came up with a military analysis of a ground option should the president request it.

According to the analysis, it would take up to 75,000 troops to secure Syria's chemical weapons facilities if they were in danger of being looted. An actual deployment would likely involve far fewer ground troops, and from various nations, but it underscores the scope of the challenge.

Before ground troops would go in, weeks of airstrikes would be needed to destroy Syria's air defenses.