Rather than prescribe a policy overseas, though, Brown emphasizes the need for more border security and says he wants to "restore America's leadership in the world."
It's not the first time Brown has been out front on an issue. He was among the first to run an ad on illegal immigration, too. That issue has cropped up in a smattering of Senate races since then.
A few other Republicans have run ads citing the threat from overseas -- often in fairly broad terms, though. And ad for Senate Minority Leader Mitch McConnell (R-Ky.) earlier this month mentioned "ISIS" alongside some other major problems that constituted "serious times," which it argued that McConnell's Democratic rival, Alison Lundergan Grimes, wouldn't be prepared to deal with.