Each year there are enough bullets produced to shoot every person on the planet twice. Seeing as it only has to take one bullet to kill someone, it seems we are making a determined effort to wipe humanity off the Earth. Plus of course killing is illegal in most countries, but then, as Voltaire said, "It is forbidden to kill; therefore all murderers are punished unless they kill in large numbers and to the sound of trumpets."
The Arms Trade is worth somewhere between $45-60 billion, and most of that is from the world's richest nations, to the world's poorest. Seeing as the rich countries are probably lending the money to the poor ones in the first place it hardly seems worth it. There is also a huge lack of accountability. Once the weapons are handed over the new owners are welcome to do what they like with them, and that includes using them against the rich nations.
The problem is, of course, that all these supposedly 'rich' countries are in debt, which means they will make money in any way they can even if it means rolling out enough bullets to wipe out humanity. It has been said that it takes courage to kill someone, now it seems it takes courage not to.