The proposed U.S. military strike on Syria has been presented as a "shot across the bow" of the Assad government, accused of using chemical weapons against its own people. Is sending a "message" reason enough to employ military force?

On Aug. 29, the Obama administration released an unclassified intelligence report presenting evidence that the Assad government used chemical weapons to kill an estimated 1,400 people, including 400 children.  According to the New York Times 

A critical piece of the intelligence, officials said, is an intercepted telephone call between Syrian military officials, one of whom seems to suggest that the chemical weapons attack was more devastating than was intended. “It sounds like he thinks this was a small operation that got out of control,” one intelligence official said.

Several officials said that the intelligence dossier about the attack also includes evidence of Syrian military units moving chemical munitions into place before the attack was carried out.

But even if the Assad government did approve the use of poison gas, there are strong concerns about whether the administration has offered a compelling explanation for what it hopes to achieve through limited military strikes.

The Times reported that the president has outlined a 

case for action both on safeguarding international standards against the use of chemical weapons and on the threat to America’s national interest.

That threat, they said, is both to allies in the region, like Turkey, Jordan and Israel, and to the United States itself, if Syria’s weapons were to fall into the wrong hands or if other leaders were to take American inaction as an invitation to use unconventional weapons.

....Mr. Obama has referred, somewhat vaguely, to reinforcing “international norms,” or standards, against the use of chemical weapons, which are categorized as “weapons of mass destruction” even though they are far less powerful than nuclear or biological weapons.

.... Mr. Obama this week has also highlighted America’s inherent right to self-defense. But some scholars warn that may be a difficult case for the United States to make.

One group of naysayers, such as the U.S. bishops, are skeptical of the value of any military intervention and advocate for a poliitical  solution involving all relevant parties in Syria, as well as foreign governments, such as Russia and Iran. Another group would only approve a strike if the U.S. can get backing from both its allies and the UN.

Finally, some critics of the president's plan contend that his goal is too vague, and is unlikely to secure any worthy or just objective -- and may even backfire or provoke unintended consequences. They come to this position from a variety of political, academic and religious perspectives, including the just war tradition.

Maryann Cusimano Love, an expert on just war theory at The Catholic University of America, raised questions about whether the proposed strike, as outlined by the president,  fulfilled the traditional criteria.

Probability of success and comparative justice (the idea that more good than harm will come of intervention) are the hardest Just War criteria to meet in the Syrian case. According to Former Ambassador Ryan Crocker as well as General Martin Dempsey, Chairman of the Joint Chiefs of Staff, any military intervention may fail. President Assad is fighting for his life, literally, so he will fight no matter what the U.S. does, using every tool at his disposal. U.S. military intervention could make matters worse, according to General Dempsey. "We could inadvertently empower extremists or unleash the very chemical weapons we seek to control."

Boston College's Father Drew Christiansen, SJ, noted the adminisration's past failure to intervene in the Syrian civil war, which has already resulted in 100,000 deaths, and asked why the chemical weapons attack had suddenly stirred the president to action.

Now if the chemical attacks were to become a pattern there would be good reason to intervene. But for one occasion, it seems to me that it doesn’t weigh up compared to those who should have been protected and haven’t been, and those who still need protection. I just don’t understand. It seems to me you need a strategic objective, which doesn’t exist, and therefore just war norms don’t apply.

The Wall Street Journal attacked Obama's description of the strike as a "shot across the bow."  Dismissing the proposal as a "pinprick" that would served little purpose, and might worsen the situation on the ground, the Journal editorial page contended that the limited approach reflected the president's desire to keep Assad in place.

We can't recall another President suggesting his goal was to miss his military target. But assuming he does want to hit something and have a military impact, our suggestion would be to take out the regime's air force. 

In National Review, Charles Krauthammer attacked Obama's effort to present the military strike as a "message" confirming U.S. resolve.

Want to send a message? Call Western Union. A Tomahawk missile is for killing. A serious instrument of war demands a serious purpose.

But Obama's proposal has also drawn support from political leaders and commentators who say it is past time for the U.S. to take action against Assad. Margaret Carlson suggested that the chorus of objections reflected the fact that many had been burned after endorosing George Bush's 2003 invasion of Iraq. Carlson asked

Are we so spooked by George W. Bush's precipitate attack on Saddam Hussein that we are now going to hem and haw about WMDs that do exist and have been used?