The climate crisis rightfully received the most focus at this week's United Nations General Assembly. But another existential threat with a potentially even quicker trigger — nuclear weapons — needs to be met with the same alacrity as global warming.

In fact, despite global nuclear disarmament being the subject of the UNGA's first resolution in 1946, proliferation proceeds in new nuclear states such as North Korea and among the nations with the largest and most lethal arsenals, the United States and Russia.

"The international arms-control framework that contributed to international security since the Cold War, acted as a brake on the use of nuclear weapons and advanced nuclear disarmament has come under increasing strain," U.N. Secretary-General Antonio Guterres said in a statement touting Thursday's International Day for the Total Elimination of Nuclear Weapons.

Seventy-nine nations have responded to the challenge by signing the U.N. Treaty on the Prohibition of Nuclear Weapons, an effort from the International Campaign to Abolish Nuclear Weapons, which endeavors to make nuclear weapons illegal under international law.

For its efforts, the once-quixotic ICAN was awarded a surprise Nobel Prize in 2017. But Washington and Moscow are going in the opposite direction, with the U.S. recently withdrawing from the Intermediate-Range Nuclear Forces Treaty, and time's ticking on renewing the New START Treaty between the U.S. and Russia that expires in 2021.

Nuclear-weapons issues "are not getting any attention from global leaders in part because historically it's been the United States that has led on this issue," Joe Cirincione, president of the Ploughshares Fund, a global security foundation that focuses on nuclear nonproliferation issues, told an editorial writer during a visit to Minnesota this week.

"But the United States has abandoned this issue of nuclear weapons," Cirincione added. "It's used as a club for justifying action on Iran and, sort of more positively, negotiations or meetings with North Korean leaders. But the [nonproliferation] regime itself, the dam that has kept us relatively safe for decades — that is falling apart."

World leaders and global citizens cannot allow it to fall apart. So just as they have put the climate crisis high on the public's agenda, activism regarding nuclear weapons needs to return, too.