{L} ast week, two U.S. F-15 fighter jets bombed a facility in eastern Syria linked to Iran’s Islamic Revolutionary Guard Corps (IRGC) and the Shiite militia proxies it supports. The strike came in response to multiple drone and rocket attacks by Iran-backed militias against U.S. positions in Iraq and Syria. “The President has no higher priority than the safety of U.S. personnel,” Defense Secretary Lloyd Austin wrote in an accompanying press release, “and he directed today’s action to make clear that the United States will defend itself, its personnel, and its interests.”

But what exactly are those interests? Are they critical to U.S. national security? And are the goals the U.S. is seeking to achieve in Iraq and Syria so important that it needs to sustain a risky troop presence there?

Ask a senior U.S. official and he will recite the usual talking points: The U.S. is in Iraq and Syria to ensure the enduring, or lasting, defeat of the Islamic State terrorist group. In Iraq, this entails training, advising, and assisting the Iraqi security forces to the point where Baghdad can prosecute what’s left of the counter-ISIS fight on its own. In Syria, the mission is murkier if not ill defined: Destroy the remnants of ISIS, prevent Syrian dictator Bashar al-Assad from retaking the eastern oil fields presently controlled by the Kurds, and promote a political resolution to a war deep into its 13th year.

If we’re honest with ourselves, most of these objectives are either pies in the sky or unimportant in the grand scheme of things. While Assad is a butcher with a French arrest warrant over his head, his forces now control most of Syria’s major cities, airports, key transit routes, all of its ports, and the vast majority of the Syrian population. The armed Syrian opposition lost its foreign patrons long ago and is now co-opted by a jihadist-aligned faction in the northwest. Frankly put: Assad will remain Syria’s dictator for another few decades (health permitting) and has next to no incentive to negotiate with his political enemies, whom he views as traitors deserving death — not fellow countrymen entitled to political concessions. U.S. partners in the region, Saudi Arabia and the United Arab Emirates included, have all come to terms with Assad’s staying power, even as U.S. policy on this front remains detached from reality.

Some argue that the U.S. just can’t afford to leave Syria lest its Kurdish partners are left open to an attack by Turkey, which has demonstrated a strong intent to carve out a 30-mile buffer zone in Syria’s north. Others make the case that U.S. credibility would be severely compromised by a withdrawal. If the U.S. left the Kurds high and dry, the logic goes, U.S. allies around the world would question whether the U.S. is truly committed to their defense.

But there are two problems with this conventional wisdom. First, Turkey is attacking the Syrian Kurds regardless of U.S.-troop presence in eastern Syria. Turkish forces have reportedly struck Kurdish areas in Syria and Iraq at least 6,000 times since 2018. Turkish aircraft went on a particularly violent spree last month, when infrastructure such as oil fields, factories, and power sources in Kurdish-administered parts of Syria were bombed in retaliation for a suicide bombing in Ankara claimed by the Kurdistan Workers’ Party. An armed Turkish drone came within 500 yards of a U.S. base in northeastern Syria, forcing U.S. troops to shoot it down. Four years earlier, U.S. troops in the Syrian border city of Kobani came under fire from Turkish artillery, which some U.S. officials suspect was a deliberate ploy to push them out of the area. In short: U.S. troop presence doesn’t seem to be restraining the Turks.

What about the credibility argument? Would U.S. credibility be shredded if the U.S. withdrew from Syria?

Although the so-called credibility thesis is a popular one in the Beltway (and in the media), it’s also wrong. As political-science professor Daryl Press articulated in his seminal work on the subject, Calculating Credibility, a nation’s actions don’t predict how it would respond in a totally different scenario. How the U.S. behaves in Syria doesn’t tell us much about how the U.S. would act in the event of a hypothetical Russian attack on a NATO member or a Chinese missile strike on Japan. Foreign leaders tend to understand that no two situations are exactly alike, and they plan accordingly. Bottom line: Post-withdrawal from Iraq and Syria, U.S. power and influence in the region would likely remain intact.

Remove all the secondary explanations, and the only legitimate reason for the U.S. to keep troops in Syria is to prevent a re-emergence of the ISIS caliphate. This would make some degree of sense if it wasn’t for the fact that it’s highly unlikely. As the Pentagon’s own special inspector general for the counter-ISIS mission documented recently, leadership losses slowed the group’s ability to plan and execute attacks. ISIS’s financial situation is increasingly perilous because of its lack of control over the population. When ISIS conducts attacks, they are unsophisticated and opportunistic, and they instigate severe counter-strikes from Russia, the Syrian army, and Syrian army–aligned militias. Those counter-ISIS operations would continue, and might even accelerate, if U.S. troops pack up and leave — not as a favor to Washington but because it’d be in the interests of Russia, Assad, the Kurds, and the various militias operating in Syria.

The Biden administration, therefore, has a fairly simple choice to make. It can do what it’s currently doing, which for all intents and purposes amounts to putting U.S. troops at unnecessary risk (there have been 33 militia attacks against U.S. positions in Syria over the past four weeks, and U.S. retaliatory strikes haven’t done anything to deter them). Or it can eliminate the risk by doing what it should have done when the ISIS caliphate collapsed more than four years ago: Declare mission success and redeploy. The first is a high-cost–low-benefit proposition; the latter is a prudent one.