If Marco Rubio is a robot, then what’s Bernie Sanders? On Sunday, CBS’ John Dickerson asked the Vermont Senator how he’d respond to North Korea’s missile test. In his answer, Sanders ignored North Korea entirely. Instead, he recited his standard talking point about opposing the Iraq War. As David Sanger has noted in the New York Times, this has become a pattern.

Ask Sanders about virtually any foreign policy subject, and he either cites his opposition to the Iraq War (and Hillary’s support for it) or spouts platitudes. When asked at last week’s MSNBC debate how long he’d keep troops in Afghanistan, Sanders replied that, “You can’t simply withdraw tomorrow. Wish we could, and allow, you know, the Taliban or anybody else to reclaim that country.” That was it. When asked later whether he had a foreign policy doctrine, he replied that, “the key doctrine of the Sanders administration would be no, we cannot continue to do it alone; we need to work in coalition.” That’s not only thin, it’s bizarre. Who thinks that under President Obama, America has been “do[ing] it alone?”

I can’t remember a presidential primary where the debates over economic and foreign policy were more disparate. On the Keystone Pipeline, the Trans-Pacific Partnership trade deal and the regulation of Wall Street, Sanders has set the agenda. He’s outlined an agenda well to the Obama administration’s left, and Hillary Clinton has followed. But on foreign policy, Sanders’ half-hearted, evasive answers have put no pressure on Hillary at all. And in so doing, he’s forfeited the left’s best chance of making her a less hawkish president.

Hillary Clinton is more comfortable sending American troops to war than either Barack Obama or the Democratic Party’s base. As Secretary of State in 2009, she urged Obama to send additional forces to Afghanistan and opposed a hard deadline for their withdrawal. In 2011, she pushed him to intervene militarily in Libya. In 2012, she suggested, unsuccessfully, that the U.S. arm non-jihadist rebels in Syria. Since leaving office, she has endorsed the Iran nuclear deal but vowed, in ways Obama has not, to intensify America’s cold war against Tehran. She’s also endorsed Benjamin Netanyahu’s demand to keep Israeli troops in the West Bank indefinitely, thus ruling out an independent Palestinian state.

In these views, Hillary reflects a hawkish liberalism that gained ascendance in the 1990s, when America’s successful wars in Kuwait, Bosnia and Kosovo gave Democratic elites a new confidence in the efficacy of military force. But the twenty-first century has not been kind to this perspective. The United States has toppled regimes in three countries since 2001: Iraq, Afghanistan and Libya. In none of them does the government America installed control the entire country. Jihadist terrorists operate in all three. And between them, these post-9/11 wars have cost the United States billions of dollars and thousands of lives.

Liberal hawks believe the trauma of these wars has made Obama too passive in Syria. But the record of recent American military intervention offers little reason to believe that the United States could have successfully cleaved Syria’s “moderate” Sunni rebels from its “jihadist” ones, and empowered them to defeat both Bashar Assad (backed by Iran and Russia) and ISIS. After all, America hasn’t even vanquished its jihadist foes in Afghanistan and Iraq, where it sent hundreds of thousands of troops.

Unlike Hillary, most Democratic voters don’t want to escalate America’s wars in the greater Middle East. They can see that, although the United States has been at war there for 15 years, the region is more dangerous, less stable and less free than it was when those wars began. If he felt more comfortable on foreign policy, Sanders would say loudly and repeatedly that those Democratic voters are right. In defending Obama’s cautiousness about military action, he could make himself, and not Hillary, the President’s heir. He could argue that America’s priority should be not fueling the region’s wars, but defusing them. He could insist that doing so requires working with Russia and Iran to end Syria’s civil war. And he could remind Democrats that unless the next President fights to keep the two-state solution alive – even if it means a fight with Benjamin Netanyahu – another full-scale war between Israelis and Palestinians is just a matter of time.

Given the leftward currents inside today’s Democratic Party – a party in which 68 percent of New Hampshire primary voters defined themselves as “liberal” compared to 56 percent in 2008 – a stronger Sanders foreign policy message could resonate. Sanders still probably wouldn’t win his party’s nomination. But by exposing Hillary’s hawkishness as out of step with grassroots Democrats, he could force her to move left, as she has on economics.

Because Sanders has not done that, this fall’s general election is likely to pit hawk versus super-hawk. The operating assumption, articulated by both parties’ nominees, will be that Obama was not tough enough. The only debate will be over how much more military aggressive the United States should be.

That’s dangerous. Today’s mainstream foreign policy debate echoes the foreign policy debate in 1960. Back then, the trauma of the Korean War was receding, just as the trauma of Iraq is receding today. Dwight Eisenhower, like Obama, prided himself on avoiding new wars. But by the end of his presidency, politicians in both parties were pillorying him as lethargic and weak. In 1960, John F. Kennedy and Richard Nixon competed to show who could more aggressively take the fight to the communists. Kennedy won, and acting on his hawkish rhetoric, launched the disastrous Bay of Pigs invasion of Cuba, and sent hundreds of Green Berets to South Vietnam.

With Rand Paul’s campaign having flopped on the Republican side, Sanders is the only candidate left who can challenge a bipartisan interventionist consensus that blithely ignores the lessons of America’s post-9/11 wars. I just wish he were doing a better job.