You mean it’s not?

Report Urges Pentagon To Arm F-35Cs With Tactical Nuclear Weapons

Foxtrot Alpha:
A report from Center for Strategic and International Studies called “Project Atom” urges the Department of Defense to make the Navy’s F-35Cs “dual role capable.” In other words, they want to make sure the jet can drop conventional munitions and nuclear ones, all in an effort to surround potential enemies with a more “neighborly” nuclear deterrent.

According to our friends over at Flightglobal, the Pentagon has only committed to making the USAF’s F-35As nuclear capable. The CSIS’s report claims that adding a carrier-based nuclear deterrent would be a “visible manifestation” of the U.S. honoring its commitment to defend its allies around the globe. Such a strategy emanates from the idea that a deterrent is more effective when it’s forward deployed to positions in and around an ally’s geographical area. Basically, a much closer proximity manifestation of the U.S. nuclear umbrella.
The U.S. has relied more and more on long-range nuclear deterrents, include land-based ICBMs, submarine launched SLBMs and heavy bomber delivered nuclear bombs and cruise missiles, with only a small fraction of the American nuclear arsenal being tactical in nature and deliverable via fighter aircraft.
HERE