President Donald Trump’s announcement Tuesday that the U.S. is leaving the Iran deal marks the end of what his predecessor, Barack Obama, considered his main foreign policy legacy.

Trump will earn credit from his supporters for keeping his promise. But in truth, the Iran deal was undone by its own terms. It did not stop Iran from enriching uranium; it did not stop Iran from building a nuclear weapon, eventually; and it did not stop Iran’s global aggression.

In fact, the Iran deal was not even a deal at all.

It was never signed by any of the parties (the U.S., Iran, France, the UK, Germany, China, and Russia). It was unclear about crucial subjects like ballistic missiles, because the “deal” was described differently by the Joint Comprehensive Plan of Action (JCPOA) and by the UN Security Council Resolutions that were meant to implement it. And, crucially, it was never sent to the U.S. Senate for ratification.

Obama’s disregard for the Treaty Clause of the U.S. Constitution was of a piece with his general disregard for the constitutional constraints on the power of the federal government and the presidency. His refusal to submit the agreement to Senate scrutiny, and his party’s abuse of the filibuster to prevent even a weak Senate vote, deepened the damage that Obamacare — his other struggling “legacy,” in domestic policy — did to American civic culture.

More than Obama’s autocratic style, what Trump ended is Obama’s legacy of appeasement.

Barack Obama came to power convinced that the United States was at best a negative force in world affairs, and at worst the cause of the world’s problems. He believed that America could be a force for good, but only if it renounced its traditional allies, abandoned its principles of freedom, and gave up its national interests in favor of rising regional powers elsewhere.

In his first year in office, Obama backed away from agreements that his predecessor had made to provide missile defense in Europe. He also reached out to the Muslim world, beginning with obsequious speeches in Cairo and in Ankara, and deep genuflection to the Saudi king. When the Green Revolution took to the streets of Iran, Obama allowed the regime to consolidate power. He criticized Israel openly while cozying up to the Cuban dictatorship.

Trump has reversed most of that. He launched attacks on Syria for using chemical weapons — policing the “red line” Obama drew but would not enforce. He withdrew from the Paris Climate Accords and exposed it as a fraud. Later this week, he will move the U.S. embassy in Israel to Jerusalem.

“The United States no longer issues empty threats. When I make promises, I keep them,” he said. Thus ended Obama’s experiment with appeasement and autocracy.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. He was named to Forward’s 50 “most influential” Jews in 2017. He is the co-author of How Trump Won: The Inside Story of a Revolution, which is available from Regnery. Follow him on Twitter at @joelpollak.