Unlike suez, the u.s. has explicit legal rights to take ANY ACTION IT DEEMS NECESSARY to protect the security and neutrality of the canal with NO requirement of consent or consultation prior with the govt. of panama. As far as the doomsday scenarios about chinese influence in canal affairs making it easier to sabotage the canal, I assume the posters have no idea how the canal operates (3 choke points/locks, disabling of any of which rendered canal unusuable), or how vulnerable the locks are to any entity with government-sized resources determined to cause havok.
I remain baffled that the best the Japanese could do to try to render the canal unusable during wwii was their swimmer torpedoes.