Last week, as the Senate Foreign Relations Committee met to consider the nomination of Senator John Kerry for Secretary of State, Senator John McCain used the opportunity to advocate for intervention in Syria. In his questioning of Kerry, McCain asserted that because the United States has not chosen to intervene aggressively against the Bashar al-Assad regime in Syria, America is at risk. Quoting a Syrian teacher, McCain said, "This next generation of children will take revenge on those that that did not help them."

This is one step beyond the so-called "gratitude doctrine," the assumption that providing assistance to those seeking to overthrow a repressive regime—especially military aid to counterbalance the overwhelming advantages enjoyed by the forces of the dictator—will produce a successor government receptive to U.S. influence and more responsive to our interests and concerns. According to this argument, the United States must intervene not even to necessarily produce a more friendly post-Assad government in Syria (which is by no means a foregone conclusion), but must take action in order to prevent the "disappointed" from one day striking the United States. Even though it is the Syrian government which is the proximate cause of their suffering, and it is Iran and Russia which have given the most assistance to the Assad regime, it is somehow America's fault—and it is against America that revenge must be extracted.

This is an amazing argument. All over the world, there are conflicts with inevitable winners and losers. In the past, the weaker side often appealed for American help and assistance on the basis of common values or by promising accommodation of U.S. interests. Ahmad Chalabi cleverly wove both streams together in his advocacy for a U.S. invasion of Iraq—both on the grounds of "spreading democracy," but also by intimating that a post-Saddam Iraq (under his leadership) would be more likely to recognize Israel, engage in the peace process, continue to contain Iran, and perhaps even break the cohesiveness of the OPEC cartel in order to bring oil prices to lower levels.

But this is the first time I have seen the "threat" argument deployed—help us in our struggle or we will target you. There is no promise of gratitude for U.S. assistance, only the implied guarantee that timely U.S. aid now will avert terrorist attacks in the future.

The Libya example should be a warning that aiding those who threaten future revenge against the United States is no guarantee of safety or security. Gratitude for liberation from Qaddafi has not produced security for Americans and other Westerners whose countries took action against the Libyan dictator.

Of course, if the United States were to intervene in Syria on behalf of the rebellion, and actively begin killing Syrians, what guarantee is there that the "next generation" of those killed and wounded by American action would not take revenge themselves? Certainly after a U.S. intervention, the losing side in the Syrian civil war—the Alawites—would also have an incentive to "take revenge" on America for their defeat and dispossession. Particularly given their past as a secretive, insular community, they would be well poised to retreat to their mountain strongholds. They could pass on to their children a desire to take vengeance for their loss unless the United States were to intervene on the ground to separate and secure the various Syrian communities and protect them against the excesses of the Sunni majority.

Of course, such a ground invasion would require a troop presence on the ground greater than the figure of several hundred thousand that General Eric Shinseki presented to Congress during planning for the Iraq war in 2003 (and for which he was publicly shot down by deputy secretary of defense Paul Wolfowitz)—a deployment no one in Congress who supports intervention is currently contemplating. Moreover, it would require the United States to be prepared to use force against those Sunnis who would want to take revenge for their suffering and persecution at the hands of the Alawis.

Taking this logic and applying it further afield also leads to complications. In Bahrain, is there not a profound sense of disappointment among the Shia that the U.S. commitment to freedom and democracy does not apply to that island nation? What would Senator McCain's reaction be if a Bahraini doctor told him, "The next generation of children will take revenge on those that did not help him." In Bahrain, of course, there are much more tangible and direct targets for action—starting with the headquarters of the Fifth Fleet. Would this lead him to support more vigorous action to depose the Bahraini royal family and create a majoritarian democracy that would bring the Shia community to power? Probably not, given the traditional close ties between the existing government of Bahrain and the United States, as well as the very real threat that the Shia of Bahrain might align themselves with Iran. What about other oppressed people around the globe, who have also been disappointed by the very real "say-do" gap between U.S. rhetorical support for freedom and the realities of U.S. policy?

In the historical record, we find that peoples who in the past did suffer from U.S. inaction have not had a track record of striking America. Have the East Timorese taken revenge for their decades-long subjugation to Indonesia, which happened under America's watch and tacit blessing in 1975? Has there been an instance of Iraqi Shia terror within the continental United States to avenge the U.S. decision not to support their uprising against Saddam Hussein in 1991? The reality is that those who wish to cause America harm will find whatever excuse or pretext to justify their attacks.

There are important and reasoned arguments for why the United States ought to intervene in Syria. This, however, is not one of them.

Nikolas K. Gvosdev, a senior editor at The National Interest, is a professor of national-security studies at the U.S. Naval War College. The views expressed are entirely his own.