In an actual war or emergency, what are the chances ISPs would refuse a presidential request? Are major ISPs typically stubborn and obstructionist in the face of major security threats, or cooperative?
In a time of emergency and war, a large multinational is not going to bite the (large and powerful) hand that feeds them.
A related current example is BP with the oil spill. BP could very well have said fuck you to the Obama administration and not set aside a compensation fund. However, this would have been done at the cost of current and future federal government contracts.
There is no justification for this bill to exist, other than because these senators decided "If China can do it, then why can't we?"