A Iranian sub (e.g.) could transfer a nuke onto a ship after it has reached the Bahamas and inspected by the Chinese company and headed to the USA.
The only way to have real national security is to inspect the ships as they arrive (or near to the coast) in the USA by US security forces (preferably the military).
Bush should spend far less money on global and domestic welfare and far more money on national security by US citizens and US companies.
Don't overreact. See post 85. The scanning equipment runs itself and the operators can't disable it either.