In commenting on President Donald Trump’s surprise announcement that U.S. military personnel will be withdrawn from Syria, it is first critical to note that no plan has been drafted, no formal order communicated, no metrics for assessing compliance defined. We have a tweet and follow-up tweets, but, as with other items in both domestic and foreign policy, it is not automatic that “So let it be tweeted, so let it be done.”

With that caveat in mind, how should we assess the proposal?

First, let me commend the Russian Embassy on a masterful job of trolling the U.S. national security community. By tweeting out support for the president’s call to rapidly pull out U.S. forces from Syria, the Russians have activated the expected Pavlovian response that the United States must by all means stay because the United States must do the opposite of whatever Moscow suggests. That series of fevered reactions distracts from the discussion we need to have, which is to focus on U.S. interests and objectives that would be served either by staying or by withdrawing.

The presence of a small number of U.S. forces on the ground in Syria is meant to provide breathing room for Syrian opposition forces that have been unsuccessful in their efforts to unseat a regime backed by Moscow; in this case, one that is run by Bashar al-Assad. It has been designed to also provide Americans with an on-the-ground presence to observe and coordinate the continued campaign against the Islamic State, which has shown willingness in the past to target Americans and U.S. interests. The strategic real estate where the United States has deployed its forces prevents Assad from regaining control of the Syrian oil deposits and complicates Iran’s ability to secure its lines of communication to Hezbollah and the Mediterranean coast. In addition, the United States hopes to be able to protect its Syrian Kurdish auxiliaries—the only reliable proxy forces Washington has at its disposal—but also influence them to avoid taking steps that cross the red lines of Washington’s NATO ally Turkey.  Finally, by having some “skin” in the Syria game, the United States makes it clear that Syria’s destiny is not to be decided by Iran, Russia and Turkey—and that the United States, too, has a vote in what happens.

Perhaps it is because of the material which I am currently working through with students at the Naval War College, but I can’t help but draw comparisons to two relevant 1980s cases: the deployment of Marines in Lebanon from 1982–84, and the continued rationale for covert, and then overt, assistance to the contras in Nicaragua.

One of the rationales for continued U.S. support to the contras after it became clear that they had no chance of overthrowing the Sandinistas was that continued pressure on the regime in Managua would force it to come to the negotiating table and moderate its behavior. If the U.S. position remains that Bashar al-Assad must ultimately leave power, but that position has become more flexible as to the timing and manner of that transition following the Obama years, then it is necessary to keep U.S. options open.

Still, I can’t get Florida Rep. Sam Gibbon’s speech on the floor of the House out of my head, the one where he thunderously declaimed, speaking of the Marines in Beirut, that “if we are there to fight, then we are far too few. If we are there to die, we are far too many.” One aspect of the current deployment follows what I have termed as the “talisman” approach to security challenges, the notion that even a “token American presence . . . will prove sufficient to dissuade any challengers from taking action.” It may be that other actors in Syria have not chosen to challenge the United States because they fear retaliation. At some point, however, that calculus may change. Would Americans support a major escalation in Syria? They didn’t support one in Lebanon. It also meant that the ambitious plans President Ronald Reagan had outlined were left by the wayside. Reagan’s plan once the U.S. mission had expanded from a presence mission at the Beirut Airport to provide reassurances to broker the withdrawal of Palestinian fighters evolved into a much more ambitious goal of getting all foreign forces withdrawn from Lebanon, getting Lebanon to sign a treaty with Israel, and ending the Lebanese civil war. (To be fair, Reagan’s first goal was achieved, but only in 2005, with the formal departure of Syrian forces from the Bekaa Valley, and not because of U.S. action.)

That comes, in part, because the various rationales for the U.S. presence haven’t connected to core interests or emotions on the part of the U.S. public. U.S. involvement in Syria has rigorously conformed to the dictates of the no-casualty/low-cost paradigm. Training Kurdish fighters, directing air strikes against ISIS targets, inhibiting Russian or Iranian action—all of this falls under the radar. So far the domestic political costs have been manageable—in part because Syria is not in the headlines.

A week before Trump tweeted his intention, however, a Washington Post story by Liz Sly—and the Washington Post cannot in any way be accused of carrying water for the Trump administration—detailed how the shift towards a more indefinite period with far more expansive mission goals than simply overseeing the final destruction of ISIS strongholds opened up “increasing risks of combat and insurgency” for U.S. forces.

And with increased risks comes increased scrutiny. What is the desired U.S. end-state for Syria? We start, of course, with optimal outcomes (Assad gone, a secular liberal democracy emerging that is pro-Western, anti-Iranian and works to restrict Russian influence), but must then assess costs. After that assessment we can decide what is essential and what can be dispensed with.

Russia has been proffering its vision: a Syria nominally under Assad’s control, but with significant areas of de facto autonomy (starting with the Syrian Kurds). Of course, there should be nothing official that would rile the Iraqis or Turks, preservation of some Iranian equities with enforcement of a series of Israeli red lines, and in this vision Russia should control the process and derive benefits (including the ability to use Syria as part of its restoration of its power-projection capabilities beyond the Eurasian space).

Much of this runs against long-standing American preferences. What will Russia’s plans cost the United States? And what consequences would the United States be willing to bear, for instance, if it insists on Assad’s immediate departure, or the complete withdrawal of Iranian forces?

This is the conversation we need to have—and the discussion Congress should be having.

Nikolas K. Gvosdev, a contributing 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.

Image: Reuters