system
Given the following post, respond as if you're commenting on Reddit:
human
[X-COM] What happens to all the arms that X-COM sells?

Avalanche missiles, blaster launchers, fusion ball UGVs, plasma hovertanks, etc., aren't these enough to threaten to cause the next World War?
gpt
All this stuff is incredibly limited in supply.

In X-Com (1994), Eulerium is explicitly stated to be well beyond the limits of human production, and can only be recovered in limited quantities from the aliens. In XCOM (2013), they're not as explicit, but the Eulerium, alloys, and weapon fragments (and Meld) must be obtained rather than produced, implying an even greater dependence on found technologies. 

All this tech is cool and all, but it's not unbeatable. Hell, a squad of veteran humans can take down a Muton with purely terrestrial technology, given the right tactics and numbers, and he's got a few hundred pounds of muscle going for him in addition to the guns & armor. The tech is good, but it's just good, not god mode. The aerial tech is probably a larger leap from what we had previously, but it's still just a few ships, and not even with any air-to-ground systems.

A few dozen plasma rifles and like 2 flying tanks is impressive, but it's just not enough dakka to destabilize the balance of power between major nations.