The details of President Donald Trump and Russian President Vladimir Putin's phone call on Jan. 28 regarding the two parties' nuclear arms reduction treaty was revealed by Reuters Thursday.

"Donald Trump denounced a treaty that caps U.S. and Russian deployment of nuclear warheads as a bad deal for the United States, according to two U.S. officials and one former U.S. official with knowledge of the call. When Putin raised the possibility of extending the 2010 treaty, known as New START, Trump paused to ask his aides in an aside what the treaty was, these sources said. Trump then told Putin the treaty was one of several bad deals negotiated by the Obama administration, saying that New START favored Russia," Reuters reported.

While Trump reportedly didn't know of New START during the call with Putin, he appeared to have at least some grasp of it in October when he used the third presidential debate with Hillary Clinton to state how Russia took advantage of the treaty.

Misnaming the pact as "the start up," Trump said during the debate:

"We're in very serious trouble because we have a country with tremendous numbers of nuclear warheads — 1,800, by the way — where they expanded, and we didn't. 1,800 nuclear warheads."

Trump might be appalled by Russia having 1,800 nuclear warheads, but according to Politifact, he's wrong about the country expanding its nuclear arsenal. "That increase is not a sign of an expanding arsenal but a temporary fluctuation caused by newer launchers replacing older launchers," Hans Kristensen, director of the Nuclear Information Project at the Federation of American Scientists, told Politifact.

Russia is engaged in a massive modernizing of its arsenal, hence its slight increase, but the U.S. has begun modernizing, as well, with nuclear experts agreeing that both sides have about the same number of warheads.

Beyond that, treaties like New START are the principal reason why Russia has merely active and reserve 1,800 warheads - rather than the 45,000 warheads the country had at its peak in 1986.

The U.S. had a similarly massive stockpile, peaking at over 32,000 in 1967. It now has about 1,400 - not including weapons awaiting disposal. At the peak of the Cold War, both superpowers mounted warheads on everything from ballistic missiles to artillery shells and land mines.

New START is the newest iteration of some of the most successful treaties in human history, pulling the world back from an arms race fraught with danger, accidents, and false alarms.

In 1969, the superpowers began negotiating the Strategic Arms Limitation Talks (SALT), which would last for three years. These talks produced the Interim Agreement, the first treaty to put caps on both sides' intercontinental and submarine launched nuclear missiles.

SALT II was signed in 1979, and sought to further limit nuclear weapons production and development. While the U.S. Senate never ratified it due to the Soviet invasion of Afghanistan, the U.S. abided by the treaty, while the Soviet Union kept building up its arsenal.

Beginning in 1982 and stretching on nearly a decade, the U.S. and Russia followed up on SALT by negotiating the Strategic Arms Reduction Treaty (START). This capped both sides arsenals at 1,600 delivery vehicles (also known as missiles and bombers) and no more than 6,000 nuclear warheads.

START I was a tremendous success, with Russia cutting its warhead stockpile down by well over half, and it was augmented by another treaty, SORT, signed by Putin and former President George W. Bush in 2002.

START expired in 2009 and was almost immediately followed by negotiations for New START, which was signed by former Russian President Medvedev and former President Barack Obama in 2010 after just a few months of negotiating. It capped strategic warhead numbers for both sides at 700 delivery vehicles and 1,500 warheads.

While Trump has spoken of winning a new nuclear arms race with Russia, he's also expressed his desire for a world without nuclear weapons and treaties like New START are the best change humanity has to achieve such a goal.