Say what? The U.S. built the Patriots and sold to Israel and it still operates what it suppose to do. The U.S. has since upgraded to be able to take on ballistic missiles which is an additional benefit especially with the proliferation of ballistic missiles these days. Saudi Arabia recently used the Patriots to shoot down ballistic missiles launched from Yemen. Israel used theirs to shoot down aircraft and uavs. I don't see any problems. No different than the U.S. Navy modifying SM-6 missiles to take down ballistic missiles besides cruise missiles and aircraft.