Senator Tom Cotton
Senator Tom CottonReuters

Arkansas Senator Tom Cotton spoke on Monday at the 2018 AIPAC conference

Cotton said the US must tell Iran it will take certain actions if problems in the 2015 nuclear deal are not solved, and that re-negotiating with Iran is not an option.

"We live in a dangerous, chaotic world," Cotton said. "It always has been that, it always will be that."

He added that "it's great to have strong...allies," but added that "no matter what" you need to have a "strong military capable of defending your country."

"One day the lion may lay down with the lamb, but until that day and actually on that day, I'd rather be the lion than the lamb," he said.

When asked whether he thinks the US has an effective strategy to counter Iran, Cotton said, the country is "moving in the right direction."

"The most fundamental point is that this administration sees Iran for what it is, an aggressive...regime that is exporting violence around the region," Cotton noted. "There's still some more practical steps to take but we've come a long way in the past 18 months."

In his opinion, terrorism is the greatest threat facing the US today, but "terrorists typically need the support of a nation-state" to cause "destruction."

"I would typically look at nation-states," he said, naming Russia and China as "great powers" and Iran and North Korea as "two rogue regimes." Though most people tend to think of North Korea as a small problem, Cotton noted that "just last week it was publicly disclosed" that North Korea had exported "a lot of chemical technology to Syria."

He did, however, note that "Iran is an even greater problem to the United States" because "North Korea is a very small isolated...country that's on the edge of the world" and is surrounded "by countries more powerful than it," whereas "Iran by contrast is a very large nation" with a "very aggressive policy."

Those factors, he concluded, make the Iranian threat more of a problem than that of North Korea.