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Any U.S. strike against Syria is “likely to last hours not days” and probably would not come before the British Parliament votes on military action Thursday, a senior U.S. defense official told Fox News.

Sources tell Fox that a strike would be led by the U.S. Navy and its assets positioned in the Eastern Mediterranean, and that it would be limited in scope.

The details about how a strike could unfold come as the administration builds its case for possible intervention in Syria, in response to an alleged chemical attack against civilians there last week.

Four U.S. Navy destroyers are in position, along with at least one nuclear-powered submarine. A British submarine is also available if Britain’s Parliament approves military action.

Air Force stand-off weapons also are likely to be used, including long range stealth bombers, according to a source.

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    Defense Secretary Chuck Hagel spoke to his British and French counterparts by phone Tuesday during a trip to Asia. In an interview with the BBC, he said the U.S. military was in position and “ready to go.”

    According to U.S. military officials, there are no plans in the initial mission to strike or secure President Bashar Assad's chemical weapons, which are spread among 50 different sites, some of which are underground.

    In fact it is not even possible, experts say, to use air strikes to carry out surgical strikes on chemical weapons storage facilities, despite suggestions from some U.S. legislators in weekend interviews that that be the preferred action. Air strikes would release those toxic chemicals into the air, potentially causing more mass casualties.

    Assad is estimated to have more than 1,000 tons of chemical weapons. Any plans to secure them would require Special Operations and boots on the ground – and neither is on the table right now, according to Pentagon officials.

    “It seems to me that what we're looking at here is sort of shock and awe light,” said Retired Major General Bob Scales, a Fox News military analyst and former commandant of the Army War College.

    “That is a simple cruise missile strike from mostly sea-delivered platforms launched outside the umbrella of Syrian air defense intended to strike high visibility targets like command and control or perhaps some missile and weapon placements.”

    The current goal, according to a senior U.S. defense official, "is to deter the regime from using chemical weapons in the future and to degrade its capabilities. ... We have a military solution for that."

    Some members of Congress are urging the administration, before proceeding, to consult with them. House Foreign Affairs Committee Chairman Ed Royce, R-Calif., cautioned that U.S. military action "could bring serious consequences or further escalation."

    Pentagon officials say that strike plans do not include regime change, so there is little need for waves of air or missile strikes over several days.

    Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey has said repeatedly that "there is no military solution" for regime change in Syria.

    According to one senior U.S. defense official, in response to reports that a window to strike could open as early as Thursday, "the window to strike is open now from a military perspective. The decision about timing is political."

    NATO has called an emergency meeting in Brussels on Wednesday. No decision to strike is likely to be made before then.

    Each U.S. Navy destroyer can carry up to 90 Tomahawks at one time. Each Tomahawk costs more than $650,000 to fire. Weather does not play a role in when a Tomahawk cruise missile can be launched.

    The problem with Tomahawks is they don't often deliver the desired effect, according to Philip Coyle, a former Obama administration official who once served as chief DoD weapons tester.

    “Mostly it's just that we don't get the result we hoped for,” Coyle told Fox. “The leader of the country, bad guy though that leader may be, doesn't give up, and so it leads to wider war. It leads to many innocent civilians being hurt or killed and doesn't produce the result we hoped for in the first place.”

    Dempsey returned early Tuesday from a pre-scheduled visit to Jordan, where he spoke about Syria with the Chiefs of Defense from Canada, France, Germany, Italy, United Kingdom, Jordan, Qatar, Saudi Arabia, and Turkey.