"According to some analysts, the development of hypersonic weapons creates the conditions for a new arms race, and could risk nuclear escalation. Given that the course of hypersonic research has acknowledged both of these concerns, why have several countries started testing the weapons?"
The answer lies in the short game. Quickest move to checkmate to get to GAME OVER. Long wars have been a problem with the cost of deployment, supply routes, tracking assets etc. Getting a destructive payload on a target has so many advantages. Taking out an operative before he can end his call. Knocking out a battalion just as it makes it's first move. Stopping a terror cell when it is still locking and loading before they reach civilian areas. Even sinking a pirate operation approaching a merchant ship. They could all be reasons for the fast and now deployment and taking control.