Scientists propose collider that could turn light into matter

You could (in principle) keep positrons and antiprotons together in a very hot plasma under magnetic confinement, but every pair that binds together into a neutral hydrogen atom can immediately escape and annihilate - turning carefully-stored fuel into gamma rays...

No, the hard part is creating the anti-matter in the first place and then cooling it down to a reasonable temperature at which it can be stored. All of our mechanisms for creating anti-matter generate anti-particles traveling at fantastic, highly relativistic speeds (and also consume much, much more energy to create then they contain in mass energy). Cooling them down without loosing them all to annihilation is very difficult. But once they're cool, it's not so bad.

The second part was simply naive. Please consider game theory.

Yours (and mine) moral is from a society with a functioning police force, rule of law and state violence monopoly. Without that, there is a clan society, where your only security is that others (generally relatives) will revenge you. A form of terror balance. Out moral just doesn't work there, since to avoid violence you have to make people believe you are ready to inflict it.

(I am unaware of a third alternative to state violence monopoly and clan societies. There are obviously places in between, with organized crime (south Italy, Mexico?). Please educate me if I miss something basic?)

Let me take an example:

There is no world police since Obama seems to be abdicating USA's partial role, countries now live in an analogue of a clan society (e.g. do alliances for protection from aggression).

Consider how Russia and China are starting the jingoism garbage again. How do you know other countries/species won't?

tl;dr: Don't take your moral instinct for logic.