When the USSR collapsed, and a lot of countries that used to be under their influence switched sides, military analysts from the capitalist block got first hand access to some of the Soviet's most advanced weapons.
Money is trust. And that's all it is. When you exchange a tangible good or a service against "money", it is only because you trust that you'll be able to exchange it again for different goods or services. The stuff that is used for money as no intrinsic value if that trust goes away. Be it gold.