Your assumption here is that actual conflict with a modern nation using conventional weaponry is possible, perhaps the majority of conflicts we have and/or the

Your assumption here is that actual conflict with a modern nation using conventional weaponry is possible, perhaps the majority of conflicts we have and/or the conflict we should prepare for, and will last more than the flight time of Nuclear warheads. I would argue that future conflicts are either proxy conflicts against less equipped forces (see Iraq, Syria, Afghanistan, conflicts with limited, focused objectives (Secure a piece of ground that is critical, say the Straits of Hormuz), and existential conflict that results in nuclear war. If it gets to the point that we are in "actual conflict" that is existential (meaning in this case specifically American survival depends on it) with a "modern nation" (I'm assuming you're talking about somebody that has nuclear weapons and a relatively developed nation state - say, China, Russia?) it would be difficult to avoid considering nuclear weapons. As a result, Aircraft Carriers might be the weapon we continue to use most as a practical matter, with our strategic arsenal backstop still in place. Probably doomsaying, but it's difficult to see it shaking out another way. I'm not saying we go straight to warheads, but anything more than testing each side in a way that leads to a negotiation likely escalates quickly.