Fusion research has not been characterized by a series of breakthroughs, but rather, slow and steady progress with limited budgets over decades.

The main candidate for a fusion reactor design today really isn't so far from the Soviet Tokamaks. We've just gotten a lot better at making very intense and uniform magnetic fields.

And some promising areas simply faded away, like inertial confinement fusion. But again, it's hard to know what would have happened with proper funding.

Just a quibble, we are in agreement on the main point!