President Donald Trump told senior administration officials he wanted a nearly tenfold increase in the size of the U.S. nuclear arsenal, according to NBC News. Trump reportedly called for restoring America's atomic stockpile —currently numbering around 4,000 warheads—to its Cold War peak of 32,000 warheads.

Secretary of State Rex Tillerson after the meeting reportedly called Trump a “fucking moron.”

The White House has denied Trump said any such thing and Trump in a tweet insisted that NBC’s report was “pure fiction.”

In any event, for the United States to grow its nuclear arsenal by nearly 30,000 warheads would be illegal, risky, complicated and, ultimately, an unprecedented waste of money.

“It would cost approximately eleventy bazillion dollars,” Jeffrey Lewis, director of the East Asia Nonproliferation Program at the Middlebury Institute of International Studies at Monterey, told The Daily Beast.

Successive presidential administrations since the late 1960s have worked hard to shrink the nuclear arsenal. A series of international treaties starting with the 1968 Non-Proliferation Treaty have required the United States, Russia and other atomic powers to halt the spread of nuclear weaponry while also limiting live tests of nuclear warheads and, perhaps most importantly, steadily reducing the numbers of nukes from the early 1960s peak.

Experts agree that constraining and cutting nukes makes the world safer and more stable by preventing a runaway arms race. Conversely, adding nukes introduces uncertainty and risk. “Essentially, global stability would be completely overturned” under Trump’s build-up, Hans Kristensen, the director of the Nuclear Information Project at the Federation of American Scientists in Washington, D.C., told The Daily Beast.

Adding 30,000 nukes “would violate major international treaties, including our [Non-Proliferation Treaty] commitments, almost certainly force us to resume nuclear testing again and signal to the rest of the world that nuclear weapons are important,” Geoffrey Wilson, a nuclear expert with Ploughshares Fund, a peace-advocacy group in San Francisco, told The Daily Beast.

Countries could decide that if they wanted to deter the United States, “they better build or seriously revitalize their own nuclear weapons programs,” Wilson added.

Even if a huge nuclear expansion weren’t geopolitically “crazy” —to borrow Wilson’s succinct assessment—it would certainly be prohibitively expensive, ultimately costing perhaps tens of trillions of dollars.

“Obama committed to replacing the existing nuclear force on an almost one-to-one basis,” Lewis pointed out. “We estimate that will cost a trillion dollars over 30 years to keep what we have and build replacements. To increase it tenfold would require massive infrastructure investments sustained over many decades.”

It’s obvious Trump didn't think through the cost and complexity of a major atomic expansion. There’s more to an effective nuclear deterrent than just piles of warheads. The Pentagon also builds and maintains rockets, bombers and submarines to actually deliver the warheads to their targets during a potentially world-ending nuclear war.

“What [Trump] reacted to apparently was the number of warheads in the [Defense Department] stockpile,” Kristensen said. “But those warheads are linked to specific delivery platforms that only have so many spaces.”

Add tens of thousands of nukes, and you have to add thousands of rockets, bombers and submarines. “If he wanted to significantly increase the stockpile size, he would either end up with a lot of nuclear warheads he couldn’t do anything with or he would have to pay for a lot of new missiles and bombers so the extra warheads would actually be used,” Kristensen pointed out.

A single new B-21 nuclear-capable stealth bomber costs around $600 million. The Air Force hopes to buy around 100 of them. Now imagine buying thousands of them, plus the subs and rockets and all the extra warheads themselves—and doing as major treaties collapse and countries rush to acquire hundreds or thousands more nukes of their own.

“That’s why his remark is so moronic,” Kristensen said. “It’s not related to the real world.”