In his speech to the South Korean legislature Tuesday, President Trump had a message for Kim Jong Un. “The weapons you are acquiring are not making you safer,” Trump told the North Korean tyrant. “They are putting your regime in grave danger. Every step you take down this dark path increases the peril you face.”

The problem is that Kim believes the opposite. It will take action, not just words, for Trump to disabuse him of that notion. Fortunately, Trump has shown there is a way to do just that. After the Syrian regime used chemical weapons on its people in April, Trump launched a military strike that took out the base from which that chemical attack was launched. The message to Syrian President Bashar Assad was clear: Use of chemical weapons will no longer be tolerated. Do it again and more military action will follow.

If Trump wants to stop North Korea’s drive for nuclear missiles capable of striking the U.S. homeland, he should look to the success of his Syrian strike as a model. He should announce that North Korean nuclear and missile tests will no longer be tolerated — that, henceforth, North Korea is a ballistic missile “no-fly zone” and a nuclear weapons “no-test zone.” Any attempt by North Korea to launch a ballistic missile will be met with a targeted military strike either taking out the missile on the launchpad or blowing it up in the air using missile defense technology. And any attempt to test a nuclear weapon will be met with a targeted strike taking out the test site and other related nuclear facilities.

Trump should make clear that so long as North Korea does not retaliate, he will take no further military action against the regime — just as he did not take further action against Assad. However, if North Korea does retaliate, then the United States reserves the right to, as Trump put it to the U.N. General Assembly, “totally destroy North Korea.”

The historical record suggests North Korea would opt for regime survival and not retaliate. After Israel destroyed Syria’s nuclear reactor at Deir al-Zour in 2007, the Assad regime essentially pretended the attack never happened. Similarly, when Israel took out Iraq’s Osirak nuclear reactor in 1981, Saddam Hussein executed Iraqi officials responsible for defense of the reactor but did not retaliate against Israel.

Both Israeli actions were part of what is known as the “Begin Doctrine” — named for then-Prime Minister Menachem Begin, who in 1981 declared that “on no account shall we permit an enemy to develop weapons of mass destruction against the people of Israel.” Now is the time to announce a “Trump Doctrine” that North Korea shall not be permitted to develop weapons of mass destruction, or the means to deliver them, against the American people.

Trump would have bipartisan support for this doctrine. Former Democratic secretaries of defense Ashton Carter and William Perry proposed a similar policy a decade ago. Just this week, former Obama director of National Intelligence Dennis Blair proposed that any further missile tests be met with “a massive American and South Korean air and missile strike against all known DPRK nuclear test facilities and missile launching and support facilities.”

Preventing such tests would be a justifiable act of self-defense. As former acting CIA director Michael Morell recently pointed out in The Washington Post, “North Korea may have the capability today to successfully conduct a nuclear attack on the United States.” We should therefore operate on the assumption that it does have this capability — and that any missile launch could in fact be a preemptive nuclear strike against the United States, which the United States has the right and responsibility to prevent.

Announcing an end to all North Korean nuclear and missile tests would take control of the situation away from Pyongyang. U.S. national security would no longer depend on unreliable assurances from the North Korean regime but rather on our military deterrent. Today, the Kim regime holds the initiative and can escalate tensions by carrying out nuclear or missile tests without consequences. Removing the regime’s ability to do so would give the initiative back to the United States and its allies and stabilize the Korean Peninsula. It could also prevent an accidental war. A test missile that North Korea intended to land in the Sea of Japan could land in Japan itself. It’s safer to take out North Korea’s missiles before launch rather than risking an accidental strike on Tokyo or Seoul.

With a Trump Doctrine declaring North Korea a “no-fly” and “no-test zone,” Trump can accomplish what three American presidents before him could not — an immediate halt to North Korea’s efforts to threaten American cities with nuclear missiles.

Marc A. Thiessen is a fellow with the American Enterprise Institute and former chief speechwriter to President George W. Bush.