The foreign policy battle between Rick Perry and Rand PaulRand PaulOvernight Defense: Military won't lift transgender ban until Trump sends directions | House passes national security spending | Russian sanctions bill heads to Trump Overnight Cybersecurity: Senate sends Russia sanctions bill to Trump | Senators unveil email privacy bill | Russia tried to spy on Macron with Facebook Senate sends Russia sanctions bill to Trump's desk MORE deepened Sunday, with the Texas governor again blasting the Kentucky senator’s “isolationist policies” during an interview with CBS News.

“He talks about basically, what I consider to be, isolationist policies,” Perry said. “And America can no longer come back onto the Continental United States, and draw a red line around the shore of America, and think that we're somehow or another not going to be impacted.”

The likely candidates for the 2016 Republican presidential nomination have traded barbs over the situation in Iraq all week.

In an op-ed for The Washington Post, Perry said it was “disheartening to hear fellow Republicans, such as Sen. Rand Paul, suggest that our nation should ignore what’s happening in Iraq.”

Perry accused Paul of being “curiously blind” to the growing threat from the Islamic State in Iraq and Syria, a Sunni militant group that has seized control of much of northern Iraq.

Doug Stafford, an adviser for Paul, dismissed Perry’s criticism as “utter nonsense” in a statement to BuzzFeed.

“Interesting to be lectured entirely in talking points though,” Stafford said. “His new glasses apparently don’t make him see the world any more clearly.”

And in a statement to CBS, Paul asked Perry, “How many Americans should send their sons and daughters to die for a foreign country, a nation the Iraqis won't defend for themselves?”

Perry said “the idea that I'm for opening up the gates and sending, you know, multiple numbers of American troops back into harm's way, is a bit of a stretch.”

“I understand as well as anyone the concept of putting our young people in harm's way,” Perry added, noting he was a veteran. “We need a strategy that is sound; we need a strategy that when we say we're going to do something, we do it. And our allies, again, can trust and our enemies fear us.”

The split between Paul and Perry over foreign policy is likely to prove one of the more interesting storylines of the upcoming Republican presidential primary, with a sizable number of voters signaling they are wary of continued military intervention in the Middle East.

Paul has fielded criticism from other establishment Republicans in recent years, with Sen. John McCain (R-Ariz.) memorably calling him a "whacko bird" for his filibuster of CIA Director John Brennan over drone policy.