Tensions between Washington and Tehran have quickly reached a boiling point in the days since last week’s U.S. drone strike, which killed Iran’s top military commander at the Baghdad airport, with worries rising that the U.S. is on the brink of war with Iran.

The Trump administration has called the attack a defensive maneuver meant to avoid what it has characterized as an imminent threat, but has refused calls to release intelligence and hasn’t detailed the evidence backing up that claim.

In the days since, Iran has vowed revenge while backing away from its commitments under the 2015 nuclear deal. The Iraqi Parliament has voted to expel U.S. troops from the country, which Biden in his speech incorrectly referred to as Iran, and U.S. officials have been forced to clean up conflicting messages about whether it would comply with such demands.

Trump has vowed to respond forcefully to any retaliation from Iran, while threatening sanctions against Iraq should it move to boot American troops. But the chaos of the last week has been entirely of Trump’s making, Biden contended on Tuesday.

“Make no mistake: This outcome of strategic setbacks, heightened threats, chants of ‘death to America’ once more echoing across the Middle East, Iran and its allies are vowing revenge — that was avoidable,” he argued.

Biden sought in his speech to outline an “honest accounting of how we got where we are,” accusing Trump of abandoning allies by withdrawing from the nuclear deal, making the U.S. an “international outlier.” He responded “erratically and impulsively” to many provocations from Iran, which in turn tried to ensure Trump’s touted maximum-pressure campaign was not cost-free, Biden continued.

While the former vice president was quick to point out that “I have no illusions about Iran” or its brutal leadership and its role in vast instability in the region, “there's a smart way to counter Iran and a self-defeating way,” he said, labeling Trump’s approach “demonstrably the latter.”

He also laid out a series of paths forward that he advised Trump to take, while conceding that the president was highly unlikely to follow his suggestions.

Biden urged Trump to move to secure a number of American assets at home and abroad, including in cyberspace, work with U.S. allies in Europe and signal hopes for de-escalation to Iran. Most critically, he said, “you have to explain your decision and your strategy to the American people. That’s your job as president, Mr. President.”

Trump’s “constant mistakes,” Biden said, have left the U.S. with a “severely limited slate of options for how to move forward — and most of those options are now bad.”

Biden argued that Trump should have more seriously weighed whether the “reward” of taking out a target like Soleimani was worth the risk of whatever happens next. But “we don’t have evidence that Trump or anyone around him thought seriously about that calculus,” he added.

Biden spoke extensively about the Iran conflict in a fundraiser at the Manhattan offices of the law firm Skadden Arps, according to a press pool report, telling attendees that the discord “just reinforces how high the stakes are in this election.”

When he later returned to the tension brewing in the Middle East, he appeared to misspeak, saying Iraq instead of Iran twice, according to the pool report.

“We can, with a little bit of luck, we can make the four years of Donald Trump appear as a historical aberration, somebody doesn't get us in a full blown shooting war with Iraq,” he told attendees.