In January, President Barack Obama’s national security adviser, Susan Rice, declared: “We were able to get the Syrian government to voluntarily and verifiably give up its chemical weapons stockpile.” Obama, she boasted, was able to “deal with the threat of chemical weapons by virtue of … diplomacy” and “in a way that the use of force would never have accomplished.”

Tell that to the children of Idlib, their lifeless eyes dilated from exposure to an apparent nerve agent that the Obama administration assured us the Assad regime no longer possessed.

“I’m very proud of this moment,” Obama declared last year of his decision not to enforce his red line and turn instead to Russia to get him out of his pledge with a face-saving agreement for Syria to give up its chemical weapons — one we now know President Bashar al-Assad violated with impunity.

The Syrian gas attack was not just a failure of Obama’s feckless foreign policy. It also was a failure of the Democrats’ arms-control agenda. For decades, Democrats have placed their faith in international agreements to control the spread of dangerous weapons. But, as we have seen in recent years, pieces of parchment, not backed by credible threat of force, are powerless to restrain murderous dictators from trying to stockpile weapons of mass destruction.

It’s not just Syria. As President Donald Trump ordered strikes against the Assad regime, he was meeting with China’s president to discuss how to deal with another Democratic arms-control failure: the North Korean nuclear threat. On Oct. 18, 1994, President Bill Clinton boasted that while “three administrations have tried to bring this nuclear program under international control,” his administration had finally succeeded in reaching a historic agreement with North Korea that would help to put an “end to the threat of nuclear proliferation on the Korean Peninsula.”

Twelve years later, North Korea exploded a nuclear device. Despite Clinton’s promises of intense verification, the North Koreans had — just like Assad — been cheating all along. They not only continued developing nuclear weapons but also became one of the world’s most profligate proliferators of nuclear technology, helping Syria to build a suspected nuclear reactor at Deir al-Zour (that was stopped not by diplomacy, but by an Israeli military strike).

Worse, on Jan. 1, Kim Jong Un announced that his regime had “entered the final stage of preparation for a test launch of an intercontinental ballistic missile” that could one day deliver such a bomb to the United States.

Once North Korea possessed a demonstrated nuclear capability, it became increasingly difficult for subsequent administrations to roll back its nuclear program. But at least we could defend ourselves by building and deploying ballistic missile defenses to protect against a North Korean attack, right?

No, Democrats said, that would violate another sacred precept in the left’s arms-control canon — the 1972 Anti-Ballistic Missile Treaty. Democrats howled when President George W. Bush withdrew from the Anti-Ballistic Missile Treaty in 2001, allowing the United States to begin deployment of defenses against rogue regimes. Unable to prevent U.S. withdrawal, Democrats did their best to limit deployment. The Wall Street Journal reported that Obama cut funding for missile defense by about 25 percent over the course of his presidency as of 2015 and eliminated critical programs that could overcome decoy missiles by placing multiple warheads on a single interceptor and destroy incoming missiles in the boost phase when they are slowest and thus easiest to strike.

As a result, we now face a rapidly emerging intercontinental ballistic missile threat from North Korea, but we are years behind the curve in terms of our ability to defend against it.

That’s not all. If you liked the arms-control failures in Syria and North Korea, you’re going to love the results of Obama’s nuclear agreement with Iran. The Iran agreement is actually far worse than the nuclear framework Clinton negotiated with North Korea. While North Korea at least had to cheat to develop a nuclear bomb, Iran does not have to cheat because Obama’s agreement does not require it to dismantle any of its nuclear facilities, end enrichment, end research and development on advanced centrifuges, permit snap inspections, or stop the development of intercontinental ballistic missiles. Israeli Prime Minister Benjamin Netanyahu has said that, far from preventing Iran from becoming a nuclear power, the Iran deal “paves Iran’s path to the bomb.”

The Democratic arms-control establishment assures us that Netanyahu is wrong. Well, it also assured us that Obama’s diplomacy had disarmed Syria, that Clinton’s diplomacy had helped to end “the threat of nuclear proliferation on the Korean Peninsula,” and that we would be safer relying on the Anti-Ballistic Missile Treaty and “mutually assured destruction” rather than ballistic missile defenses.

Feeling safer yet?

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