“If President Trump withdraws from Reagan’s INF accord, it could jump-start fielding of new technologies that would have skirted the letter of the treaty, like ground-launched hypersonics. But it could also lead to less exotic solutions that the INF pact now bans outright, like mid-ranged ballistic missiles. As the product of a very particular moment in the Cold War, the misleadingly named Intermediate-Range Nuclear Forces accord actually bans all cruise and ballistic missiles — . It doesn’t matter whether they carry nuclear warheads or conventional ones — that have a range between 500 to 5,500 kilometers, about 310 to 3,417 miles….but if and only they’re launched from the land. The exact same weapon, launched from a ship, submarine, or aircraft is completely legitimate.”
A 2013 Pentagon report states that the termination of the treaty would open up four new possibilities. The first is the modification of “existing short range or tactical weapon systems to extend range.” Many missiles launched from the sea or air already operate in this range, and land-based systems could be quickly modified to match them. The second possibility is the return of “forward-based, ground-launched cruise missiles (GLCMs) that could be fired from existing Aegis Ashore missile defense systems with simple alterations. Third is the return of “forward-based, ground-launched intermediate-range ballistic missiles (IRBMs), which would require new designs and constructions as similar missiles were destroyed according to the INF agreement. The final possibility created by withdrawal from the treaty are “forward-based, ground-launched intermediate-range missiles with trajectory shaping vehicles (TSVs),” which essentially add “maneuvering and glide capabilities” for guiding it towards its target.
It is impossible to predict what kind of impact the return of these capabilities would have or the U.S. vis-a-vis Russia and China, but it is possible that they could either escalate ongoing tensions in certain border areas or serve as threats that bring opponents to the negotiating table, as they did in the Soviet era.