Syrian opposition: Top U.S. Army general alternative.

Top U.S. military officials have identified the risk and benefits of American military involvement in the conflict in Syria is possible.

Joint Chiefs of Staff Chairman Gen. Martin Dempsey, the five proposed options, including military strikes, and the establishment of a limited no-fly zone.

But he said the use of force in Syria will be. "Nothing less than an act of war" and could cost billions of U.S. dollars.

Washington has so far ruled out military intervention in Syria.

Its role in the conflict is currently limited to delivering humanitarian aid to Syrian refugees in neighboring countries and providing assistance to Syrian opposition is not dead.

Syrian opposition: Top U.S. Army general alternative.