On Friday, Secretary of State John Kerry took a shot at likely presumptive GOP presidential nominee Donald Trump, particularly for his proposed border wall, during his commencement address at Northeastern University in Boston.

Kerry warned the grads not to be susceptible to “soundbite salesmen” and “carnival barkers” and argued walls are not a cure-all for United States’ security.

“Many of you were in elementary school when you learned the toughest lesson of all on 9/11,” Kerry said. “There are no walls big enough to stop people from anywhere, tens of thousands of miles away, who are determined to take their own lives while they target others.”

“So I think that everything that we’ve lived and learned tells us that we will never come out on top if we accept advice from soundbite salesmen and carnival barkers who pretend the most powerful country on earth can remain great by looking inward and hiding behind walls at a time when technology has made that impossible to do and unwise to even attempt,” he added.

Kerry went on tell the grads to prepare for a “complex and borderless world.”

“For some people, that is all they need simply to climb under the sheets, close their eyes and push the world away,” Kerry said. “And shockingly, we even see this attitude from some who think they ought to be entrusted with the job of managing international affairs.”

“The future demands from us something more than a nostalgia for some rose-tinted version of the past that did not really exist in any case,” he said. “You’re about to graduate into a complex and borderless world.”

Follow Jeff Poor on Twitter @jeff_poor