Comment by mrtracy

There are tantalizing ways to create fusion which don’t require these precise conditions. For example, a simple farnsworth fusor device gets fusion reactions just by causing atoms to cross paths at super high speed until they collide - they simply don’t collide often enough to release anywhere near a net energy gain.

Inertial confinement fusion, such as the National ignition facility, does generate comparable pressures and temperatures to the core of the sun within the fuel pellet for an extremely small moment during an implosion. This is done by focusing a lot of energy on small target.

Plasma confinement techniques don’t utilize high pressure to create fusion; they rely on extreme temperatures which are significantly hotter than the core of the sun, which can produce fusion events in a plasma which is only pressurized to around 1 atmosphere (they also rely on different fuel types than the sun which fuse much more readily). The key is once again focus, a large amount of energy is put into a small amount of gas. The obvious issue with this is that the extreme temperatures would destroy any physical container rapidly - but given the electromagnetic nature of plasma, it can be contained using a strong magnetic field without reaching the surface of its physical container.