Grassroots pressure has forced President Obama to seek approval from Congress for an attack on Syria. But Obama is hell-bent on ordering a missile assault on that country, and he has two very important aces in the hole.

The administration is about to launch a ferocious propaganda blitz that will engulf a wide range of U.S. media. And as a fallback, the president is reserving the option of attacking Syria no matter what Congress does.

Until Obama’s surprise announcement Saturday that he will formally ask Congress for authorization of military action against Syria, the impassioned pitches from top U.S. officials in late August seemed to be closing arguments before cruise missiles would hit Syrian targets. But the pre-bombing hyper spin has just gotten started.

The official appeals for making war on yet another country will be ferocious. Virtually all the stops will be pulled out; all kinds of media will be targeted; every kind of convoluted argument will be employed.

Hell hath no fury like war-makers scorned. Simmering rage will be palpable from political elites who do not want to see Congress set an unprecedented precedent: thwarting the will of a president who wants Pentagon firepower unleashed on another country.

President Obama and top Democrats such as House Minority Leader Nancy Pelosi will twist every arm they can to get a "yes" vote for attacking Syria. Meanwhile, most mainline media pundits, numbingly addicted to war, will often chastise and denigrate foes of authorization.

But we have a real chance to prevent a U.S. attack. One cogent argument after another, from intelligence veterans and policy analysts and weapons experts, has debunked the messaging for war on Syria. And some members of Congress – not nearly enough, but some – have begun to speak up with cogent opposition.

One of NPR’s inside-the-box hosts of "All Things Considered" on August 30 asked Rep. Zoe Lofgren (D-Calif.) about the Obama administration’s claim that missile strikes on Syria would be "a limited action" and not "war." Congresswoman Lofgren replied: "I think that anyone who argues that shooting missiles and dropping bombs on another country is not an act of war has got some further education warranted. If somebody shot cruise missiles at Washington for only one day, we would still consider it an act of war, wouldn’t we?"

Not many members of Congress have Lofgren’s clarity, and many of their votes on authorization are up for grabs. Each of us can help affect the outcome by demanding that our senators and representative oppose the war resolution. We should make our voices heard in all sorts of public venues.

The president’s move for a congressional vote should cause a major escalation of anti-war activism. A straw in the wind: during just a few hours after Obama’s announcement on Saturday afternoon, nearly 10,000 people took the initiative via RootsAction.org to email members of Congress with a "No Attack on Syria" message.

National opinion polling and momentum inside Congress indicate that we can defeat Obama’s war resolution. It’ll be a tremendous fight, but we can prevail.

But even if Obama loses the vote in Congress, there’s a very real danger that he will proceed with ordering an attack on Syria.

Burying the lead almost a dozen paragraphs into a September 1 news story, the New York Times mentioned in passing: "White House officials indicated that Mr. Obama might still authorize force even if Congress rejected it."

A careful reading of Obama’s Rose Garden announcement on Saturday verifies that he never quite said he will abide by the decision of Congress if it refuses to approve an attack on Syria. Instead, the president filled his statement with hedging phrases, detouring around any such commitment with words like these:

"I have decided that the United States should take military action against Syrian regime targets. … And I’m prepared to give that order. But … I’m also mindful that I’m the President of the world’s oldest constitutional democracy."

"I will seek authorization for the use of force from the American people’s representatives in Congress."

"Over the last several days, we’ve heard from members of Congress who want their voices to be heard. I absolutely agree. So this morning, I spoke with all four congressional leaders, and they’ve agreed to schedule a debate and then a vote as soon as Congress comes back into session."

"And all of us should be accountable as we move forward, and that can only be accomplished with a vote."

"I’m ready to act in the face of this outrage. Today I’m asking Congress to send a message to the world that we are ready to move forward together as one nation."

At the grassroots, people across the United States will be working very hard to prevent congressional approval of an attack on Syria. That activism is imperative. But we should also understand that Obama has not committed himself to abide by the decision that Congress makes.

Norman Solomon is co-founder of RootsAction.org and founding director of the Institute for Public Accuracy. His books includeWar Made Easy: How Presidents and Pundits Keep Spinning Us to Death. Information on the documentary based on the book is at www.WarMadeEasyTheMovie.org.