Sen. Rand Paul (R-KY), a key ally of President Donald Trump’s in the U.S. Senate, plans to force a senate vote regarding the Trump administration’s new more-than-$100 billion Saudi Arabian weapons deal announced on the president’s foreign trip.

In an exclusive interview with Breitbart News in his U.S. Senate office on Capitol Hill on Tuesday, Paul explained how he will do it and why:

There’s an arms export legislation from the 1970s and it gives the power to one senator to ask for a vote if they object to an arms sale. I think that by selling Saudi Arabia more arms, we further the arms race. We encourage more arms to be bought on both sides of the arms race. I think that there’s evidence that Saudi Arabia has been involved with terrorism. One of the leaked emails from Hillary Clinton was her saying that ‘my goodness, Saudi Arabia and Qatar are funding ISIS in Syria—we need to do something to get them to quit funding these radical groups. So there’s a lot of evidence. There’s even evidence going back to 9/11. Sen. Graham—Bob Graham—said that he thought that there was from the 28 pages and other evidence that there was a great deal of evidence pointing to Saudi Arabia’s government actually being involved in 9/11.

When asked to explain what he means by the “arms race” in the Middle East, Paul told Breitbart News that the various factions of Islam have been “killing each other” for a millennium and America should not help it along. Paul said:

In the Middle East, everybody is arming up. Israel has nuclear weapons, and Israel has hundreds if not thousands of ballistic missiles. Iran has ballistic missiles. Saudi Arabia has ballistic missiles. But as we give more weapons to Saudi Arabia, the reaction from both Israel and Iran is ‘well, gosh, if Saudi Arabia has more, maybe we need more?’ It ratchets up. Saudi Arabia already has weapons that they point at Tehran and Tel Aviv. They actually have Chinese missiles that you can see from satellite photos aimed at Tel Aviv and pointed at Tehran. I don’t know—I just don’t think we need to encourage it. The place is such a stinking mess over there. They’ve been killing each other for a thousand years. I just don’t think feeding their fury with more weapons is a good idea.

Paul previously used this exact tactic—forcing a Senate vote on a Saudi weapons deal—toward the end of the Obama administration to limited success. While only a quarter of the Senate backed him up, in the end the Obama administration changed part of the deal.

The senator went on to say:

We’ve done this one time previously, last fall, and I think we got about 25 votes to stop the sale. But interestingly, the publicity and the debate that developed around it—President Obama, who had sold more weapons to Saudi Arabia than all of the previous presidents combined, changed his mind after hearing the debate. So our hope is after public participation, that maybe the public will say: ‘Why are we doing that? Why are we involved in another war in Yemen?’ I think it’s enough on our plate to try to do something about ISIS than to get involved in another war in another country.

Paul did praise President Trump’s efforts to get Saudi Arabia on board with the fight to destroy ISIS and said his speech in Riyadh was great, but that the president may run into serious problems since Saudi Arabia is not likely to change their ways from previous support of such groups.

“I think it is a good idea that he’s telling and encouraging the people who live there to do something about ISIS, if Saudi Arabia would do something about it,” Paul said. “The problem is in the past Saudi Arabia has actually been supporting radical groups like ISIS. I don’t really trust them to do it. Also, in the neighboring country of Yemen, they’ve been indiscriminately bombing. I’m afraid they’ll use some of our weapons to bomb civilians. About six months ago they bombed a funeral procession, killing 124 civilians and wounding 500. I don’t want that to be done with American weapons. I think that gives us a black eye in the area and it actually may create more terrorists than it kills.”