The idea of using surface ships as part of the force received criticism in Europe, who felt that surface ships would be vulnerable to attack, while a wholly submarine force would be more difficult to eliminate. President Kennedy argued that using only submarines would defeat the purpose of minimizing American control of the force, as the United States was the primary power capable of building the requisite number of submarines and training their crews. Including surface vessels would allow for greater European involvement in both construction and training, argued Kennedy, who also dismissed the notion that an entire pan-Europe nuclear-armed fleet could be eliminated before any of them could commit retaliatory strikes.