A frontal view of four B-61 nuclear free-fall bombs on a bomb cart at Barksdale Air Force Base. United States Department of Defense SSGT Phil Schmitten On Thursday, President-elect Donald Trump tweeted that "The United States must greatly strengthen and expand its nuclear capability until such time as the world comes to its senses regarding nukes."

But as Kingston Reif, director for disarmament and threat reduction policy at the Arms Control Association, told Business Insider, there's a huge contradiction in Trump's recent thinking on defense projects.

"Trump may be open to expanding the number of nuclear weapons in the arsenal, building new weapons, increasing the role of nuclear weapons in US policy," Reif told Business Insider in an interview, despite the fact that the US's nuclear arms are already "second to none."

However, the US's current path towards modernizing US nuclear weapons will already cost a whopping $1 trillion dollars. Though it's not yet clear whether Trump means actually building more or different types of nuclear weapons, he also recently seemed to shun another potentially trillion-dollar US defense project that's already well underway.

"One of the interesting contradictions here is that his tweet suggests that he is going to move full steam ahead with the current nuclear modernization plan, but we’ve also heard him express concerns about the F-35 program, saying maybe we need to stop it," said Reif.

But, as Reif points out, the F-35 is part of the US's overall nuclear modernization program.

"Later versions of the F-35 will be nuclear capable and replace other fighters and bombers,' said Reif.

Thus begging the question: How can Trump support making our nuclear forces "stronger" without supporting the F-35?

The F-35 promises to bring a quantum leap in the US's airpower, and other US allies and NATO countries will fly the revolutionary plane as well.

F-35B Marine variants land on the USS America. Lockheed Martin

F-35 pilots who spoke to Business Insider have asserted unequivocally that the F-35 is the price of admission to great power conflicts of the future, and that the only people critical of the program these days are those who have never sat inside the plane.

In fact, the F-35, slated to carry B-61 gravity bombs, will make the nuclear weapons relevant again, as currently no plane in the US arsenal can carry the bomb, which the US already has hundreds of.

Trump seems not to be "putting two and two together there," according to Reif.