Once the aliens got wind of the gigantic weapons sales that US arms dealers and their Pentagon procurers were selling to fuel a new century of wars, the capitalist's best friend, the little blue doctors decided to even the sides a bit.
Nuclear powered flying saucers with thermonuclear weapons have been donated by the thousands to the countries that the US arms sales had placed at a disadvantage.
Weak or unpopular nations have been chosen by the moon men and Martians for massive arming. The advanced weapons can outfly, outshoot and outbomb any and all existing weapons on planet Earth.
The aliens are said call the radical plan: Peaceful Coexistence through a Balance of Power.