Between this intentional move to differentiate himself as a candidate and his spotlight on the border issue, the alternate headline could be “Rick Perry officially announces 2016 run.” There’s no other explanation for his choice to specifically pick a fight with Rand Paul over what Perry flatly calls “isolationism.”

Report from the CSMonitor:

Since then, he’s been considering another run for the White House, weighing in on important issues, as he did this week in meeting with President Obama about those thousands of Central Americans – many of them children – streaming into the United States, crowding into detention facilities, and raising more questions about this country’s failed immigration policy.

Also this week, Gov. Perry laid out some of his ideas about US foreign and national security policy while taking on Rand Paul, the leader among 2016 GOP presidential hopefuls and an outlier among Republicans in how the US deals with the rest of the world.

Writing in The Washington Post, Perry said, “I can understand the emotions behind isolationism.”

“Many people are tired of war, and the urge to pull back is a natural, human reaction,” he wrote. “Unfortunately, we live in a world where isolationist policies would only endanger our national security even further.”

“That’s why it’s disheartening to hear fellow Republicans, such as Sen. Rand Paul (Ky.), suggest that our nation should ignore what’s happening in Iraq,” Perry continued. “The main problem with this argument is that it means ignoring the profound threat that the group now calling itself the Islamic State poses to the United States and the world.”

Paul “advocates inaction,” Perry charged, “going so far as to claim … that President Ronald Reagan’s own doctrines would lead him to same conclusion. But his analysis is wrong. Paul conveniently omitted Reagan’s long internationalist record of leading the world with moral and strategic clarity.”

For Perry to toss out terms like “isolationist” and accuse Paul of ignoring what is going on in Iraq is as close to a direct attack in a Republican primary as you can get.