Introversion

tl;dr: Is it possible to win the game even if you lose your fleet?

I've noticed that generally when a player loses most or all of his Battleships and Carriers, the enemy fleet destroys his silos and the game ends.

Is it possible to regain initiative by using your continental air force or perhaps a first ICBM strike? So far I've tried nuking the enemy fleet to lessen their advantage or to strike using bombers on whatever military installations I know, but this is very hard to do when the powers are separate by oceans (if not impossible in some cases, bombers have a limited range).

Usually when I destroy a navy, the opponent practically gives up and just wastes nukes to bring the victory timer or even does a rage quit. How can I convince such person that the game is still worth playing after losing the majority of your navy?

Although I haven't done so against a human, I just beat an ai where I intentionally never placed my fleet...

I was NA and my opponent was SA, if that makes any difference

It depends on what assets you have at your disposal. Regardless of whether or not you have anything besides your silos, 9 times out of 10 the wisest decision you can make would be to launch all of the ICBMS you have at the opposing player's cities. Do not target their silos even if you know where they are because your assets are limited and your objective in this game is not to destroy installations, it's to kill as many people as possible. Now ultimately you may question this logic as it exposes your silos but depending on what assets you have left this can be overcome. In particular, if you have any sub or air assets you may be able to destroy or damage the opposing player's silos. Once you make the decision to launch the opposing player either has to launch immediately or wait until the entirety of your act has been completed. If they launch even a couple minutes after you they will expose their cities without missile defense protection while letting you recover your missile defense capability. If they wait until your attack has completed they will be forced to launch a counterattack if the Victory Timer has been initiated. If the Victory Timer has not been started then you have more assets that you can use in defense against that counterattack or as counterattack to their own counterattack. The more time they use, the more time you have to coordinate and plan. There has been many a time that I have lost my entire Navy but still won the match by using this strategy to force the issue.