The announced withdrawal of both the United States (US) and Russia from the two-nation Intermediate-Range Nuclear Forces (INF) Treaty, is not a necessary requisite to an arms race. The withdrawal of both nations forges hope of an emergence of an even wider nuclear pact, involving more nations pledging to eliminate more classes and types of nuclear weapons.
Full consideration should be given to the likelihood of a nuclear weapon eliminating treaty between the US, Russia, China and others. Hence, with the failure of the INF Treaty, an opportunity now exists for wider world engagement and involvement in respect to the inherent dangers of nuclear weapons despite claims that they are deterrents to conflict. They are weapons of mass destruction and should be treated as such carriers of grand calamity.
Russia's assertion that it would now develop hypersonic medium range missiles amid its announced withdrawal from the INF Treaty, is preposterous, economically crippling and dangerous. If Russia, then the Soviet Union, failed to take note of its economic disadvantage to compete with the Ronald Reagan era Star Wars program, then Russia could suffer a second economic woe in spearheading a new arms race.
While China might fare better than Russia in any new arms race with the US, nuclear proliferation could set humanity back many years in terms of other developments - infrastructure, environmental protections, healthcare, education and other scientific innovations.
Therefore, rational thought, preferring the continuity of the human species on Planet Earth, suggests a wider nuclear pact entreating more nations to reject nuclear proliferation, thus eliminating more classes and types of nuclear weapons, as the safe and viable alternative to the defunct INF Treaty.