The treaty -- concluded in 1987 by then US president Ronald Reagan and Soviet leader Mikhail Gorbachev -- limited the Cold War powers' medium-range missiles, both conventional and nuclear.
The United States will officially withdraw from the Intermediate-Range Nuclear Forces (INF) Treaty on Friday, clearing the way for a new arms race with Russia - and throwing China into the mix.
The treaty - concluded in 1987 by then US president Ronald Reagan and Soviet leader Mikhail Gorbachev - limited the Cold War powers' medium-range missiles, both conventional and nuclear.
United Nations Secretary General Antonio Guterres called the demise of the treaty a dangerous step that "will likely heighten, not reduce, the threat posed by ballistic missiles."
"When it expires tomorrow, the world will lose an invaluable brake on nuclear war," he said on Thursday.
US President Donald Trump's administration says the treaty is effectively dead already because of Russian violations -- a charge Russia denies. The White House launched the six-month procedure for leaving the treaty on February 1.
"I think the INF Treaty has served us well, but it only works if both parties comply," new US Defense Secretary Mark Esper said recently.
"The United States will remain in compliance with all of our obligations until August 2nd - and after that point in time, we will continue to pursue what is in our best interest," he told lawmakers.
Under the deal, missiles with ranges of 500 to 5,500 kilometres were eliminated.
That paved the way for the mothballing of Russian SS-20 missiles and American Pershing missiles deployed in Europe.
Even if European nations have expressed concerns about the consequence of a new arms race, NATO has endorsed the US position, saying Russia's 9M729 missile had violated the INF agreement.
Moscow insists the new projectile has a maximum range of 480 kilometres -- within INF parameters.
But the death of the INF treaty may suit Washington, former defence secretary Ash Carter said in early July.
"From the military point of view, not the political point of view, it's not so bad," Carter said at a conference at the Council on Foreign Relations.
"We can make good use of what we call conventional prompt strike."
On Thursday, Trump told reporters that the INF did not even come up when he talked by telephone with Putin about Russian wildfires on Wednesday.
However, he did suggest vaguely that a new treaty may be in the mix.
"Russia would like to do something on a nuclear treaty and that's ok with me. They'd like to do something and so would I," he said.
The Pentagon is thrilled that it will now be able to modernize its arsenal to counter the mounting might of China, which is looking to assert its military supremacy in Asia.
"Most of China's inventory is of intermediate-range missiles and so we need to make sure we have the capability as well to respond should we -- God forbid -- get in a fight with them one day," Esper said.
The United States has pledged not to deploy new nuclear-armed missiles in Europe. But it has made no such promise on the deployment of conventional weapons.
Advances in technology have allowed for the development of mid-range missiles that are much more precise than those made 30 years ago, explained career diplomat William Courtney, who is now a senior fellow at the nonprofit, nonpartisan Rand Corporation.
"The technology has changed so much that is makes it militarily attractive," said Courtney, an arms control expert.
For Thomas Mahnken, a professor of strategic studies at Johns Hopkins University's School of Advanced International Studies, the United States must now deploy medium-range conventional weapons on its islands in the Pacific and other territory controlled by its allies.
Such a move would help counter China's rise, especially in the South China Sea, where the People's Liberation Army has effectively commandeered several disputed islands.
"It is time to turn the tables," Mahnken said in a commentary published on the specialist website War on the Rocks.
"Such weapons, capable of denying China the use of littoral waters, would be a powerful deterrent to Chinese aggression."
Such a move seems to have the support of the next chairman of the US joint chiefs of staff, General Mark Milley.
When asked by US senators about the imminent demise of the INF Treaty, he said he supported the deployment of conventional ground-based medium-range missiles in the Indo-Pacific region.
"Do you think those would be helpful?" one senator asked.