To make absolutely sure that no belligerent or antagonist nation or group of nationsn ever even considers the option. So that they will know, without a shadow of a doubt, that from the land, from the air and from the sea, they will suffer five times over whatever they develop and consider dishing out to us.
For this reason, our Trident nuclear deterrent should remain strong at 18 ships all with Trident II D-5 missiles. We should have two or three times as many B-2 and B1-B's and we should have the Peacekeepr numbers increased with a mobile version deployed.
Once SDI is in place and shown to work reliabily, we may then consider cutting back a portion of our triad. Not until IMHO and then only the oldest weapons.
My position is that we should maintain an unassailable position from which we can operate and bow or posture or disarm for no man or nation.
Just my opinion.