If the strikes are not strong enough, this will only strengthen the position of war supporters — at least when it comes to capturing eastern Ukraine. On the other hand, if the strikes on Moscow are somehow incredibly powerful, that too will bolster the pro-war faction, though in that case the focus would shift to forming entirely new structures in place of Ukraine.
Trump, however, likely assumes that limited strikes on Moscow could serve as a signal to the Kremlin to agree to a fragile peace with Ukraine, similar to what happened with Iran, thereby postponing a full-scale conflict in Europe indefinitely — leaving the problem for future U.S. presidents to resolve. In the meantime, Trump would focus on extracting resources in Ukraine and force European companies to invest in military production there, preparing the country for a future war.
There may be other options as well.