If the Americans feel? Well this alone should make russians feel compelled to strike first and you to crap your pants.Going first limits the damage of the retaliatory strike. If the Russians launch 100 nukes instead of 1000, they have to choose targets instead of not bothering to choose targets. Idaho might be OK in this scenario and the surviving Americans wouldn't need to worry about potato shortages on top of everything else.
If the Americans feel that Russia is about to launch and they need to make a choice between the two nightmare scenarios of "Our country is about to be destroyed and the survivors won't have enough potatoes to eat" and "Our country is about to be destroyed, but we can probably save the potato industry", then obviously it's in their interest to choose the latter. It's the least bad of two terrible situations and they have the potential to save something.
It does not, however, give them enough of an advantage to factor into planning that a first strike is a viable military option since better first strike capabilities does not mean that MAD no longer applies, it just means that the D is slightly smaller.
I am sorry but I don't feel you have adequate excuse for development first strike capabilities.
Are you serious? I have difficulty reading that as a serious response.
If you feel that a nuclear strike is imminent and your choices are:
A) Get hit by 1000 nuclear weapons
B) Get hit by 100 nuclear weapons
Is there any reason that you would not do what you can to ensure B?
I mean, the rationale as to why militaries develop first strike capabilities, even when they don't actually plan to strike first without provocation, are so trivially obvious that they're not even worth listing out.
Do you think that Russians don't warplan out first strike scenarios and develop technologies to allow them to better do it? Even Canada thinks up first strike plans in the event that they're needed - sure, those plans tend to consist of "Find out where Bob parked the tank and get someone to fill it up with gas before we drive into Buffalo, New York to take over", but we still have those plans.
I really just don't get your question.