We have 42 active Los Angles class hunter-killer submarines

[HooptieWagon]

68. If you can accurately predict the date and nature of the next attack,

you have a bright future as a DoD consultant.
The reality is: we don't know for sure. Where will Russia be 10 years from now, if Putin stays in charge? What will happen if China continues to build up naval forces? What if N Korea figures out how to build missles that work? Waiting until the attack occurs is too late to say "Gee, lets start building submarines".
The LA boats still in service range from 16 to 31 years old. 17 of the earliest ones, built in the 70s, have already been retired. They do not have accomodations to account for woman sailors and officers. Submarines will be a part of the naval forces for the foreseeable future. Woman are going to be a part of the Navy for the foreseeable future. Bit by bit the obsolete LA boats are being replaced with modern subs. If the US were to be attacked, I don't want the Navy to have to respond using 60s technology, nor do I want them to lack enough ships or manpower.