Would Tomahawk navigation work without GPS?

Does Tomahawk have an inertial navigation system?

Yes. Inertial navigation provides a way to operate when GPS is unavailable or has been disrupted.

The Iowa counterfactual raises the question of whether its cruise missiles require a satellite system that does not exist in the earlier period. Inertial navigation is identified as an alternative to dependence on GPS. The exchange then distinguishes early military use of GPS, including the first Gulf War, from the later completion of full global coverage.