Speaking at Northeastern University commencement ceremonies on Friday morning, U.S. Secretary of State John Kerry advised newly-minted graduates that the world is on its way to becoming “borderless” and that the critical issues of our time are terrorism, poverty and, of course, climate change.

“I am honored this morning to address a university family that thankfully is one very utterly unafraid to look beyond our borders and into the future,” told a Boston Garden crowd of about 25,000, reports The Boston Globe.

Kerry advised graduates that a border wall would not deny entry to terrorists.

“Many of you were in elementary school when you learned the toughest lesson of all on 9/11,” he said, according to The Washington Examiner. “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.”

The former Massachusetts senator warned that “dangers like climate change, terrorism and disease do not respect borders or any of the norms of behavior.”

Kerry then took some veiled — and totally unveiled — shots at presumptive Republican presidential nominee Donald Trump.

“I think that everything that we’ve lived and learn tells us that we will never come out on top if we accept advice from sound-bite salesmen and carnival barkers who pretend the most powerful country on Earth can remain great by looking inward,” he said.

“For some people, that is all they need: simply to climb under the sheets, close their eyes and push the world away,” he also 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,” Kerry declared. “You’re about to graduate into a complex and borderless world.”

Kerry also called this year’s crop of seniors at Northeastern — which includes graduates from 77 different countries — “the most diverse class in Northeastern’s history.”

[dcquiz] “In other words, you are Donald Trump’s worst nightmare,” Kerry wisecracked.

Audience members enthusiastically waved flags from many nations far-flung, including China, Vietnam and South Korea, the Globe notes.

The cost for a year of tuition, fees and room and board at Northeastern University is about exactly $60,000. It is slated to increase next quite a bit in the fall.

Time has printed Kerry’s Northeastern commencement remarks in full.

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