Sen. Rand PaulRand PaulTrump: 'No doubt' we'll make a deal on healthcare Overnight Defense: General says US strike probably led to civilian deaths | Tillerson to push NATO on spending | Trump taps F-35 chief Senate backs Montenegro's NATO membership MORE (R-Ky.) on Thursday shot back at Sen. John McCainJohn McCainMcCain responds to North Korean criticism to calling Kim Jong-un 'crazy fat kid' Overnight Finance: Dems seek probe of acting SEC chief | Defense hawks say they won't back short-term funding | Senate seen as start point for Trump infrastructure plan | Dems want more money for IRS Overnight Defense: Pentagon considers more troops for Afghanistan | McCain, Graham won't back short-term funding | GOP defends Trump rules of engagement MORE after the Arizona Republican accused Paul of working for Russian President Vladimir Putin.
"I think he makes a really, really strong case for term limits," Paul said on MSNBC's "Morning Joe." "I think maybe he's past his prime; I think maybe he's gotten a little bit unhinged."
McCain made the claims Wednesday from the Senate floor.
"The senator from Kentucky is now working for Vladimir Putin."
"We currently have ... combat troops in about six nations. We have troops actively just stationed in probably a couple dozen others," he said.
"We have a $20 trillion debt."
Paul said McCain's foreign policy would "greatly endanger" the country and "greatly overextend us."
"And there has to be the thought whether or not it's in our national interest to pledge to get involved with a war if Montenegro has an altercation with anyone," he said.
"Another argument is that, when you ask the people of Montenegro, only about 40 percent or slightly less are actually in favor of this," he said, adding there are a lot of considerations.
"But to call someone somehow an enemy of the state or a traitor might be considered by most reasonable people to be a little over the top."