There is simply no way, officials say, to effectively conduct computer operations without entering networks inside the United States.
The process could ultimately be accepted as the digital equivalent of customs inspections, in which passengers arriving from overseas consent to have their luggage opened for security, tax and health reasons.
Administration officials have begun to discuss whether laws or regulations must be changed to allow law enforcement, the military or intelligence agencies greater access to networks or Internet providers when significant evidence of a national security threat was found.
The complications are not limited to privacy concerns.