President Donald Trump parted ways with his hawkish national security adviser John Bolton on Tuesday, ending a 17-month tenure that included additional troops deployed to the Middle East, saw the U.S. repeatedly threaten “military action” against the Venezuelan government, and brought the country within minutes of bombing Iran.

In May 2018, less than two months after Trump announced Bolton’s appointment on Twitter, Bolton achieved part of his dream when the Trump administration pulled out of the Iran nuclear deal and set U.S.-Iran relations on a path toward escalation. According to a New Yorker profile, Trump’s decision to abandon the agreement meant so much to Bolton that he hung a framed copy of the executive order in his office.

The strategy that defined Bolton’s tenure was to torpedo the slow work of diplomacy and position the U.S. as aggressively as possible, no matter the results. U.S. adversaries would capitulate to the demands. With Iran — a country Bolton has long recommended bombing — experts say his efforts have backfired and pushed the country to renuclearize.

Since the U.S. implemented sanctions designed to drive Iranian oil exports to zero and cripple the economy, the Iranian government has neither collapsed nor yielded to U.S. demands. After designating the Islamic Revolutionary Guard Corps a terrorist group, after new troop and carrier deployments to the Middle East, after a U.S. cyberattack against Iran, after the U.S. downed an Iranian drone, and even after Trump tweeted that the U.S. had nearly bombed Iran, the Trump administration’s aggressive posturing at Bolton’s behest has not paid off.

Experts have said that Iran is no closer to denuclearization than it was two years ago. Just two days ago, Iran announced that it would speed up its already restarted uranium enrichment. And far from being restrained, Iran has seized tankers, shot down a drone, and continued its support for militias across the Middle East.

Bolton’s policy record is equally unimpressive on Venezuela, where the Trump administration seeks the ouster of President Nicolas Maduro’s regime and has thrown its support behind self-declared “interim president” Juan Guaido. Bolton said the U.S. military needed to be “ready to go” in Venezuela. But since a planned May 1 uprising dubbed “Operation Freedom” by Guaido fizzled into a series of street protests, Maduro’s position appears as strong as ever.

An Axios report in July suggested that, from Trump’s perspective, Bolton’s aggression was the main reason to keep him around. Trump is said to have joked about Bolton’s bloodlust with foreign leaders, saying things like, “John has never seen a war he doesn’t like.” Such lines signaled that if people didn’t like Trump’s methods, they might have to deal with bad cop Bolton.

Trump and Bolton reportedly parted over policy disagreements on Iran, Afghanistan, and North Korea. Trump tweeted that he “disagreed strongly with many of his suggestions.” It’s difficult to predict where U.S. foreign policy will go next under Trump. But it’s possible that Bolton’s most lasting impact will be the fallout from his open contempt for international institutions.

Bolton’s recess appointment as United Nations ambassador in 2005 was widely viewed as a sign of the George W. Bush administration’s contempt for the institution. (Bolton had famously remarked that if the U.N. headquarters “lost 10 stories, it wouldn’t make a bit of difference.”)

Bolton has been vocal about his disdain for the U.N. and international law in general. In a 2018 speech at the Federalist Society, Bolton told the audience that “the largely unspoken, but always central, aim” of the International Criminal Court was “to constrain the United States,” and promised to let it “die on its own.” During his time with the Trump administration, the U.S. took the extraordinary step of denying visas to ICC investigators and announced that it was withdrawing from the U.N. Human Rights Council. The Trump administration has continued to look for ways to scale back funding for U.N. aid programs.