The JWST cost about 3 times as much as the NIF. The annual budget for the NIF is about the cost of 6 F-35s, which the US is acquiring 152 of in FY2022. It's not getting top-priority money.
OK, I don't think comparing research to the defense budget is at all useful, but comparing JWST research to fusion research IS. So I'll stand corrected on US money.
However, ITER is a global effort, so it isn't just the US budgets we have to consider, right?