The Intermediate-Range Nuclear Forces Treaty succumbed to its injuries today. It was 32 years old.

Six months ago, Donald Trump and Vladimir Putin put the INF Treaty on life support, and they could have resuscitated it at any time. Instead, they let the treaty expire.

The INF Treaty was conceived in the White House on December 8, 1987, and born seven months later to its proud guardians, Ronald Reagan and Mikhail Gorbachev. Almost immediately, it was obvious that this nuclear-weapons treaty was special. While many of its older siblings lacked ambition, the INF Treaty was bold and expansive. It required the US and USSR to reduce their nuclear arsenals, eliminate an entire category of missiles, and establish on-site inspection mechanisms.

 Within three short years, the INF Treaty led to the destruction of 2,700 missiles and banned either side from deploying new ones of that type. It reduced the threat of nuclear war, and would continue to do so long after Reagan and Gorbachev had moved on.

The latest heirs of the treaty, however, didn’t care for it the same way. Feeling slighted by the US decision to kill the Anti-Ballistic Missile Treaty in 2002, Vladimir Putin took his frustrations out on the INF Treaty. In 2014, the United States publicly claimed that Putin had violated the terms of the treaty by building and deploying a prohibited type of missile. In retaliation, Putin fired off accusations of his own, dubiously claiming that the United States had also violated the treaty.

Over the years, arguments over the treaty flew back and forth, and eventually the living situation became untenable. This year, Trump gave up on the INF Treaty, opting to kill it instead of talking through his concerns with Putin. It appears that his decision was swayed by John Bolton—a known killer of arms-control deals. In February 2019, the United States officially suspended its INF Treaty obligations, and Russia followed suit the next day—triggering the six-month withdrawal process that led to the treaty’s death today.

During that six-month period, there was no attempt to save it. On Wednesday—just two days before its death—Trump and Putin spoke on the phone, but neither mentioned the INF Treaty.

In all likelihood, the death of the INF Treaty will jumpstart missile production on both sides. Putin has reportedly already deployed nearly a hundred INF-violating missiles within his territory, and the Trump administration plans to test an INF-violating missile of its own later this summer.

The INF Treaty will be missed; it helped keep us safe from nuclear war for 32 years. It is survived by only one other US-Russia nuclear weapons treaty—New START—which has capped US and Russian nuclear arsenals since 2011. If nothing is done, New START will expire in February 2021. Its life could be easily extended, but Bolton is advising against it.

If Trump allows New START to wither away as the INF Treaty did, in February 2021 there will be another obituary to write. And on that day, the world will enter a new era without any limitations on the two largest nuclear arsenals on the planet. Let’s hope it doesn’t come to that.