[DennisP]

In the 1950s they said fusion was around the corner, because they were just getting started and didn't understand the problems yet.

In the 1970s they said it was 30 years away, but conditioned that on a much higher level of funding than they actually got. For the level of funding they got, they said it would never happen.

Now we have a very good understanding of tokamak plasmas, and some new enabling technologies including much better superconductors.

[pfdietz]

And in the 1980s, it was pointed out that fundamental limitations on power density will likely keep any DT fusion reactor from being competitive.