"the process that powers the sun is recreated and controlled here on Earth"
sounds kind of dangerous...i mean, what if the thing exploded, with the power of the sun, wouldnt that kill millions of people?
Thats precisely the problem.
Nobody's yet figured out how to control the chain reaction from going runaway.
Another major technical difficulty has been that there's no 'container' that can hold or contain the ionized hydrogen nuclei anymore. Even magnetic fields breakdown at those physical extremes (we're talking 10 million kelvin - the temp at which the strong nuclear force breaks down). In the sun's case (and that of all stars) its gravity that holds the continuos nuke explosion in one place but how dya do that here on earth??