“The American people must have a reasonable assurance that the U.S. has a compelling national interest to intervene,” Daniel Dellinger, the American Legion’s national commander, said in a statement. “And that we have clearly defined political objectives. The potential costs, both in terms of lives and treasure, are too great to ask otherwise.”

The Legion has about 2.4 million members with 14,000 posts across the country. It was chartered and incorporated by Congress in 1919.

“We’re encouraged to see President Obama working with Congress on whether to take military action against Syria. Committing American forces to combat is a decision that must be taken only after careful deliberation,” Dellinger said.

“On top of severe budget cuts — and after more than a decade of war in Iraq, Afghanistan, Libya and elsewhere — our military is already strained.”

The Legion, along with the Veterans of Foreign Wars, expressed support for the Iraq war in 2007, saying patience was needed to let the surge work.

The founder and CEO of the Iraq and Afghanistan Veterans of America (IAVA), Paul Rieckhoff, tweeted Sunday, “I've yet to see a clear argument explaining why it can't be France leading a military action in Syria.”

A spokeswoman told The Hill Tuesday IAVA doesn't have a position on Syria right now.

IAVA has more than 200,000 member veterans and civilian supporters, its Facebook page says.

Other major veterans groups have not voiced their positions on Syria.

--This report was updated at 9:10 p.m.