Former Vice President, and current Democratic frontrunner Joe Biden, suddenly finds himself — on the defensive after the killing of Iranian General Soleimani.

In the early hours after President Donald Trump ordered a drone strike that killed Iran’s top military official, the Democratic presidential field responded pretty much in unison, condemning the president’s actions, and saying that the move was a miscalculation that had the potential to destabilize the region further and put the lives of Americans and their allies at risk of deadly reprisal.

But, as the potential blowback against the United States became clearer in the days following the death of General Qassem Soleimani, the leader of the Iranian Quds Force and architect of Iran’s war against ISIS across the region, candidates began to divide themselves into two distinct camps: those who argue that only a steady, experienced hand can steady America’s increasingly erratic foreign policy, and those who point to the past two decades of U.S. foreign policy to show the need for drastic change.

That division is now largely aimed at Biden, whose admittedly long career, includes having gotten the US mired in wars in Iraq and Afghanistan. As a former two-term vice president and a major figure in U.S. foreign policy during his decades in the Senate, Biden is particularly vulnerable to attacks on historic U.S. foreign policy as examples of “what not to do.”

“Age does not necessarily correlate with wisdom on foreign policy,” one foreign policy adviser to a “top-tier candidate” told The Daily Beast. “Over the course of years, and in some cases decades, there is a track record that is extensive—and in some cases it is consistent—in pointing to flaws of judgment, and perhaps even a worldview that is not necessarily well-suited to what is required of a commander in chief.”

As we teeter on once again getting involved in the Middle East, not surprisingly, the candidate throwing the most shade at Biden on foreign policy, is Bernie Sanders.

For years Sanders has touted his 2002 vote against authorizing the use of military force in Iraq. Even in the days before the strike that killed Soleimani, when foreign policy was still very much on the back burner for most presidential hopefuls, Sanders had described Biden’s support for the war as “a lot of baggage.”

“I was right about Vietnam. I was right about Iraq. I will do everything in my power to prevent a war with Iran,” Sanders tweeted on Friday morning, alongside a video in which he describes that war and the vote that authorized it as “the worst foreign policy blunder in the modern history of the United States.”

Sen. Elizabeth Warren (D-MA) and former Mayor Pete Buttigieg, both of whom entered politics long after public opinion and political consensus turned against the invasion of Iraq, have been more implicit in their criticism, instead warning that Soleimani’s death risks an escalation of military tensions with Iran that could result in another “endless war”—like “the one Biden voted for.”

The Biden campaign, however, told The Daily Beast that they see the emergence of foreign policy matters as a central issue in campaign politics as a boon, rather than a burden.

“These events put into greater relief that we need a commander-in-chief who can, from the moment they’re sworn in—and without needing on the job training—start repairing the severe damage that Donald Trump has done on the world stage,” a campaign spokesperson told The Daily Beast.

On Friday, Biden’s response to a reporter’s inquiry about his role in the 2011 operation that led to the death of Osama bin Laden prompted further questions about whether his foreign policy experience is a help or a hindrance. In an exchange with Fox News correspondent Peter Doocy, Biden said that he would be willing to use an airstrike to kill a terrorist leader, using the bin Laden operation as an example. When Doocy followed up by noting that Biden has previously said that he discouraged President Obama from authorizing the operation, Biden brusquely responded, “No, I didn’t. I didn’t.”

However, there are reports that Biden – some of out of his own mouth – that he had not backed the operation in a group meeting at the time.