After much deliberation I went for phaser. Even though we have 3D printing and the beginnings of lab grown meat/organs, replicators like those in trek are a long way off yet.
The only country so far to experiment with laser tech is the US. They already have on mounted on the front of a jumbo jet that can nail ballistic missiles and aircraft from many miles away. I think a man portable device is a few decades away yet. The power required to blow something up with a laser is enormous.
As far as I'm aware there are no laws governing the use of laser based weapons in warfare as the weapons do not yet truely exist in a capacity where they can be used in open warfare.