To hear President Trump’s political opponents describe it, the decision to decertify the Iran deal is a major miscalculation — a needlessly provocative action that could even bring all-out war.

As is often the case, their assessment is 180 degrees off the truth. With good reason did Mr. Trump say, in effect, “enough is enough.”

The deal that the Obama administration helped forge with Iran in 2015 is, in fact, helping to destabilize an already-dangerous region. If anything, it’s increasing the chances that war could break out.

As Mr. Trump noted in his address, Iran “remains the world’s leading state sponsor of terrorism, and provides assistance to al Qaeda, the Taliban, Hezbollah, Hamas and other terrorist networks. It develops, deploys and proliferates missiles that threaten American troops and our allies. It harasses American ships and threatens freedom of navigation in the Arabian Gulf and in the Red Sea. It imprisons Americans on false charges. And it launches cyber-attacks against our critical infrastructure, financial system and military.”

It would be one thing if Iran’s behavior had moderated in the wake of the Iran deal. But can we point to some concrete actions that show the regime is ratcheting down its support of terrorism, or acting less belligerently toward the United States and its allies in this war-torn region? We can’t.

Not that this is surprising, considering Iran’s history. Too many Americans have either forgotten or aren’t old enough to remember when agents of the regime captured the U.S. embassy in Tehran in 1979 and seized more than 60 Americans hostages — a crisis that stretched out for 444 days.

For more than a year, America sat there with egg on its face. The hostages were finally released just as President Reagan took the oath of office. The hostage-takers displayed no fear of President Carter, but they wisely opted not to provoke the Gipper.

Iran has continued to exert a destabilizing influence ever since. The 2018 Index of U.S. Military Strength describes it as “an anti-Western revolutionary state that seeks to tilt the regional balance of power in its favor by driving out the Western presence, undermining and overthrowing opposing governments, and establishing its hegemony over the oil-rich Persian Gulf region.”

And thanks to the Iran deal, it’s a richer state as well. Besides lifting nuclear-related sanctions, the 2015 agreement gave Tehran access to about $100 billion in restricted assets and allowed it to expand its oil and gas exports. This sanctions relief boosted Iran’s economy. In May 2016, Tehran announced that it was increasing its military budget for 2016-17 to $19 billion — a 90 percent increase over the previous year.

Today, its ballistic missiles pose a major threat to U.S. bases and allies — from Turkey, Israel and Egypt in the west, to Saudi Arabia and the other Gulf states to the south, and Afghanistan and Pakistan to the east. The deal that Mr. Trump has decertified has done nothing to alleviate this danger.

Critics of Mr. Trump’s actions call him a “rogue,” but the fact is, he talked to our allies, and is doing what he can to accommodate their concerns without betraying America’s interests (which, after all, is his main job).

He didn’t ignore them. He didn’t preemptively pull out of the deal, as he could have in the wake of his campaign promise to junk the deal. No, he talked with our allies, and took a middle course that could be portrayed by some of his supporters as breaking a promise — and simply decertified the deal (for now). That kicks it to Congress, which now has the chance to nix or fix this weak agreement.

“History has shown that the longer we ignore a threat, the more dangerous that threat becomes,” Mr. Trump said in his address. He’s right. It’s time to change course and make the Middle East more secure, not less.

Republished from The Heritage Foundation.