If there is one thing Bernie Sanders never fails to reference in the Democratic primary, it’s Hillary Clinton’s vote in favor of the Iraq war. He brought it up after answering a question about gun control, he continually references the vote during Democratic debates and he’s made his opposition to the war a cornerstone of his foreign policy. Last week he said, “I don’t think you are qualified if you have voted for the disastrous war in Iraq,” and on Sunday, he again questioned Clinton’s judgment based on her vote.

The response from some journalists and Clinton supporters has been to derisively question whether he has any other notes, with a tone of: when is he going to stop complaining about something that happened over a decade ago?

He shouldn’t stop. If anything, more politicians should be bringing up the Iraq war at every opportunity. The dismissive tone Clinton supporters have taken to the issue belies a callous indifference to the most disastrous foreign policy calamity in our lifetime – a decision that continues to directly affect US foreign policy across the entire Middle East. It is dangerously shortsighted and an insult to the countless people who died as a result. If anything, we should be talking about the Iraq war more, not less.

Four thousand five hundred members of the US military died in the Iraq, tens of thousands of Americans were injured or maimed, and at least a half million Iraqis died as a result of the decision to declare war (some estimates put it as high as one million), for starters. Should we stop talking about those unspeakably tragic deaths because most happened 10 years ago, or because the majority of them weren’t American?

But beyond the direct destruction caused by Congress and the Bush administration committing more than a $1tn of blood and treasure, it is beyond debate that the current chaos Isis is sowing across the Middle East can be directly attributed to the Iraq invasion, something that even the most hardcore Iraq war architects, like former British prime minister Tony Blair, readily admit.

Isis’s roots can be traced to the squalid US jails that sprouted up in Iraq in the early 2000s, and at least a portion of the terrorist group’s leadership consists of members of Saddam Hussein’s Ba’ath party who were excommunicated from the Iraqi army and civil society following the US invasion, widely considered to be one of the worst decisions by the US occupying forces.

What’s more, it’s clear our elected officials seem to have barely learned anything from the Iraq war despite all this. Much like Iraq, the Obama administration, spurred on by the then secretary of state Hillary Clinton, bombed Libya and helped depose Muammar Gaddafi, helping lead to the Isis hotbed that the country is today. The answer to the complex problems in Syria by Clinton and the Republicans seems to be that we yet again need more military action to fix what our military action caused in the first place.

Furthermore, more US troops are now trickling back into Iraq. And the only lesson that Congress seems to have taken to heart is “don’t vote on military action at all, and instead let the president use ever-expanding executive power to bomb countries without a check on his or her power”.

Instead of questioning why Sanders constantly returns to the Iraq war, the real question should be: why don’t more politicians bring up the Iraq war? And why aren’t most of us retaining the lessons we should learn from our recent history? Far from being obsolete, the Iraq war influences almost every facet of Middle East policy today.