When President Donald Trump appeared in Alex Jones' online talk show in 2015, the Republican presidential candidate made a promise to the Dallas-born conspiracy theorist: "I will not let you down. You will be very, very impressed."

But Jones, a right-wing extremist with a vast following, unleashed a vulgar tirade against Trump on Friday over the president's decision to launch missile strikes in Syria as a civil war there rages on.

Expletive-laden rants are a staple of Jones' Infowars.com. This time, however, there seemed to be tears.

"I just feel like I had my best girlfriend break up with me," Jones said. "And the left will make jokes, but this ain't funny, man."

As Jones went on, he sighed, his face reddened and his voice faltered.

"That's what makes it so bad," said the Austin-based conspiracy theorist. "If he had been a piece of crap from the beginning, it wouldn't be so bad. But we made so many sacrifices, and now he's crapping all over them. It makes me sick."

Alex Jones, conservative conspiracy theorist and operator of Infowars.com, in the control room for his right-wing radio show, in Austin. (Ilana Panich-Linsman/The New York Times)

Trump announced Friday that the United States, France and Britain had fired missile strikes in Syria to punish President Bashar Assad for an apparent chemical attack against civilians. Pentagon officials said Friday's attacks targeted the heart of Assad's programs to develop and produce chemical weapons.

Earlier this month, dozens of people choked to death in the rebel-held suburb of Douma near Damascus. Videos of the attack's aftermath, along with interviews with residents and medical workers, suggested that the Syrian government had dropped canisters that released "some sort of chemical compound," The New York Times reported.

The Syrian government has denied responsibility, while the Russian military claimed that the attack had been staged and directed by Britain.

Jones, who notoriously called the 2012 Sandy Hook Elementary massacre a hoax, told his viewers that Trump had been given fake intelligence — all made up, he said, like the false narrative about weapons of mass destruction in Iraq 15 years earlier.

Damascus skies erupt with surface to air missile fire as the U.S. launches an attack on Syria targeting different parts of the Syrian capital Damascus, Syria, early Saturday, April 14, 2018. Syria's capital has been rocked by loud explosions that lit up the sky with heavy smoke as U.S. President Donald Trump announced airstrikes in retaliation for the country's alleged use of chemical weapons. (Hassan Ammar / The Associated Press)

The talk show host blamed the Douma deaths on Islamic extremists but offered no evidence. As he railed against Trump, he played a clip of the president's televised speech about the Syria strikes.

"Assad launched a savage chemical weapons attack against his own innocent people," Trump said.

Jones asked someone to hit the pause button.

"No, he didn't," Jones said. "There is no proof. Show it. Show it, you [expletive] liar."

And even though Jones had insisted during the first 43 minutes of his nearly three-hour show that he was no "drama queen," he pounded his desk with his fist.

"Show me the proof, [expletive]!"

In his rambling rant, Jones claimed Trump had been compromised by special counsel Robert Mueller's investigation into whether the Trump campaign colluded with Russia. He suggested Trump wouldn't get a warm reception on his show again.

"When push came to shove, you put your tail between your legs; you crapped your pants," Jones said. "Doesn't mean I hate your guts, but let me tell you, if you ever call me again, I'm gonna tell you I'm ashamed of you."

The Associated Press contributed to this report.