In this March 31, 2018 photo, Syrian citizens walk in front of buildings that were destroyed during the battle between the U.S.-backed Syrian Democratic Forces fighters and Islamic State militants, in Manbij, north Syria. (AP Photo/Hussein Malla)

President Trump’s recent decision to withdraw all 2,000 U.S. troops from Syria epitomizes his administration’s deeply flawed foreign policy. The president’s abrupt and reckless decision was reportedly reached against the guidance of U.S. military leaders, including Defense Secretary James Mattis. As Mattis asserted in his resignation letter, a worldview defined by “treating allies with respect and also being clear-eyed about both malign actors and strategic competitors” is incompatible with the Trump’s views. In other words, Trump’s withdrawal from Syria is a betrayal of our allies and a boon to our adversaries. It’s not “America First” in any respect. Rather, it’s an “Iran and Russia First” policy.

Trump lacked a coherent strategy and defined objective in Syria before his abrupt troop-withdrawal announcement. While a bipartisan group of members of Congress welcomed Trump’s limited military response to Bashar Assad’s use of chemical weapons in April 2018, in the eight months that followed, Trump’s Syria policy has been meandering and ill-defined at best. At worst, it has directly played into the hands of our adversaries, especially now that we have telegraphed to Islamic State, Assad, and others an imminent U.S. military retreat. This is precisely the critique that Republicans — including Trump — had of President Barack Obama’s decision to withdraw U.S. troops from Iraq. The one key difference, however, is that Trump’s withdrawal has come at a time of American isolation and weakness, when we are lacking the international alliances essential to defending our national security interests.

The results of this flawed decision are significant and mounting. A complete withdrawal of U.S. troops from Syria will lead to the further diminution of American credibility and leadership in the world, and may lead to a sharp increase in regional security threats. The 2,000 U.S. troops stationed in Syria were a deterrent to Russian and Iranian overreach in the region and provided the U.S. with vital intelligence and a strategic foothold in a historically volatile neighborhood. The withdrawal of U.S. troops from Syria will provide Iran with its long-sought land corridor from Tehran to the Mediterranean. In the absence of U.S. troops, the land continuum between Iran, Iraq, Syria, and Lebanon now gives Iran unimpeded access across the region.

Regional actors who rely on the U.S. for their security, especially Israel and the Kurds, now must fend for themselves against Islamic State, Assad, Iran, and its proxy militias. Even worse, Trump appears unfazed by the security implications of his decision. During his recent visit to Iraq, Trump said Israel was capable of providing for its own defense. Referring to Israel, Trump said, “They’ve been doing a very good job for themselves,” seemingly unconcerned that a U.S. withdrawal from Syria creates new defense burdens for Israel.

Trump’s withdrawal from Syria counters the best interests of the U.S., Israel and other allies in the region because it shifts strategic realities on the ground. The so-called buffers on Syria’s southern border with Jordan and southeastern border with Iraq — where U.S. Special Forces had been stationed — will soon be erased. In eastern Syria, Iran will have direct access to arm and supply its proxy terrorist organization, Hezbollah, opening yet another front for potential regional conflict. With tens of thousands of missiles already stationed on Israel’s northern border with Lebanon, Israel must now also contend with Hezbollah on its border with Syria. Former Israeli Defense Minister Avigdor Lieberman recently warned that Trump’s decision to withdraw U.S. troops from Syria increases the risk of a major military confrontation between Israel and Iranian-backed forces. Even Islamic State, which lost its territory in northern Syria and has been relegated to disparate bands of fighters, can now reconstitute. The withdrawal of U.S. troops has laid the foundation for the resurgence of Islamic State and other terrorist organizations.

Trump’s Syria retreat is also symbolically problematic, as it represents the ceding of U.S. global leadership to our adversaries including Russia, which has been aiming to control Syria since it entered its civil war in 2013. Trump reportedly made his decision based on assurances from Turkish President Recep Tayyip Erdogan that Turkey would continue to battle Islamic State in Syria, which directly contradicts Trump’s erroneous claim that Islamic State has already been defeated. The fact that Trump acquiesced to Erdogan and blatantly ignored the advice of U.S. military and intelligence officials is alarming. Perhaps worse is that it directly contradicts U.S. national security adviser John Bolton’s assertion just three months ago that the U.S. would not leave Syria “as long as Iranian troops are outside Iranian borders, and that includes Iranian proxies and militias.”

For more than two years, Trump has touted his “America First” foreign policy. But his abrupt decision to withdraw U.S. troops has laid bare an uncomfortable truth: Trump’s foreign policy contradicts America’s best interests, abandons our allies, and benefits our adversaries. This truly is an “Iran and Russia First” policy, and the consequences are grave and dangerous. It is now incumbent on members of Congress to intervene, conduct meaningful oversight of the executive branch, and check Trump’s reckless abdication of U.S. leadership. America’s national security, and that of our allies, depends on it.

Ron Klein is chairman of the Jewish Democratic Council of America and a former U.S. representative from Florida. Halie Soifer is executive director of the Jewish Democratic Council of America and a former national security adviser in the Senate and Obama administration.