We can duplicate this with thermonuclear weapons, where the detonation of a fission device temporarily provides the required temperature and pressure.

In the laboratory, intense magnetic fields compress the fuel to the appropriate conditions, although it appears that instabilities in the generated plasma quickly arise making its continuous containment impossible.

This method, using laser implosion of fuel pellets, seems to be promising, but it also involves an extremely complex Rube Goldberg process which may simply not be achievable on an industrial scale.

There are other problems, too. For example, how do we extract useful energy from the process AFTER the fusion takes place? How do we clean up the waste products so that the apparatus can be used again, often enough for continuous power generation? Granted, fusion does not produce dangerous wastes like fission, but they still must be removed so the process can be repeated.

I am not optimistic about fusion. It may be possible to solve these problems, but we have no guarantee they will be solved, or even that they can be solved. We have to come to grips with the concept that just because a process does not violate physical law does not necessarily mean we can exploit it for practical use. There is no law of nature that says our engineering will eventually catch up to our science. This may have been true in the past, but it may not be the case in the future. Our ability to understand nature may very well exceed our ability to control it.

Or more prosaically, it may turn out to be a matter of simple economics: the cost of doing something may eventually exceed the value we derive from doing it.

The human race is grown-up now. We may have to learn to recognize our limits as well as our potential.