The Democrats’ latest presidential primary debate proved it: they’re still the party of imperialism.

There were heated disputes over domestic policy, including important questions such as universal healthcare, wealth taxes and climate policy. But Democratic candidates were as one in their support for the projection of US force around the world. They differed on tactics, but not on principles – they are all vying to be commander-in-chief of the biggest imperialist power the world has ever seen.

The test came during a discussion of Turkey’s invasion of Syria, just days after president Donald Trump ended US military support for the Kurdish movement in north-east of the country. For years, Kurdish militias received significant military support from US imperialism. In exchange, they fought local adversaries while refusing to be drawn into any adventures that would cause diplomatic trouble or threaten greater “regional instability”. For example, they had a longstanding de facto arrangement not to engage the fascist forces of Syrian president Bashar al-Assad. Now that the US has withdrawn support, the Kurds face a military assault from Turkey and have moved toward a firmer alliance with the Syrian government and therefore Assad’s sponsor: Russia.

For the Democratic establishment, disengagement is one of Trump’s greatest crimes. In an extraordinary outburst, former vice president Joe Biden described Trump’s order to withdraw US troops as “most shameful thing any president has done in modern history”. Really? It’s not even the most shameful thing a president has done in the last 20 years, let alone the last century.

Is it more shameful than the obliteration of Iraq, which resulted in a million people dead? (Biden voted for that.) Is it more shameful than the global “war on terror”, with its kidnappings, torture chambers and remote-controlled assassinations? (As Obama’s vice president, Biden was up to his neck in drone-led imperialism.) Come to think of it, is it much more shameful than the last few times the US walked away from a temporary alliance with Kurdish nationalists?

Biden and the other Democrats don’t care about the Kurds – or anyone in the Middle East faced with extreme imperialist violence. They hate Trump’s decision because it has strengthened the relative influence of America’s rival, Russia. The US, they worry, now looks less terrifying when terrifying the world is America’s job. In the debate, Minnesota senator Amy Klobuchar farcically suggested that Trump’s indifference to the Kurds would make the nuclear-armed apartheid state of Israel worry that it might not receive full-throated US support in the future. That would be nice, but it’s not what’s going on.

For most of the last century, the Democrats have been the world’s foremost imperialist political party. They supported the Gulf Wars and NATO’s bombardment of Yugoslavia. The Vietnam War was largely the creation of two great heroes of liberal Democrats, John F. Kennedy and Lyndon Johnson. Even America’s conversion into the world’s biggest imperialist power, with military bases, spies and client dictatorships all around the world was masterminded by the administration of that great Democratic icon, Franklin Roosevelt, and that of his successor, Harry Truman – the godfather of NATO.

In many ways, the debate was a re-run of 2016, when Hillary Clinton complained that Donald Trump wasn’t tough enough to take on Russia. What, then, of the more left wing frontrunners, Elizabeth Warren and Bernie Sanders? Neither offered even mild critique of US imperialism. Warren positioned herself as a typical imperialist technocrat, complaining that Trump has “cut and run on our allies”. Sanders said only that “what [Trump] has done is wreck our ability to do foreign policy, to do military policy, because nobody in the world will believe this pathological liar”.

In this context, the maverick congresswoman Tulsi Gabbard stood out for her attacks on “regime change wars” and the Democratic establishment’s foreign policy. Her stridency illuminates how close both Warren and Sanders are to the mainstream on the fundamentals of imperialism, even when they differ with right wing Democrats. But Gabbard is not anti-war, and she's not anti-imperialist. Like Sanders and Warren, she criticises the strategy employed for projecting US power. But, like the others, she wants to administer that power, not disarm it.

Nobody in their right mind believes that the US military acts in the interests of democracy or human rights. America’s “ability to do foreign policy, to do military policy” is a euphemism for furthering the interests of US capitalism by coercion and extending imperial power by force. As the Kurds have again discovered, anyone is expendable in the pursuit of those goals. Talking about that would mean stating the truth about the US empire, about its role in the world and about the Democratic Party’s longstanding record as an enthusiastic hangman of liberation movements across the globe.

Unsurprisingly, none of the three frontrunners for the Democratic presidential nomination wanted to discuss that.