But China is rich and has tons of gold reserves to pay Iran with. Moving gold is risky for individuals, but manageable for governments, certainly big powerful

But China is rich and has tons of gold reserves to pay Iran with. Moving gold is risky for individuals, but manageable for governments, certainly big powerful ones like China or India. The question is not whether it's more risky than a wire transfer but whether, when a wire transfer isn't possible, gold is workable. I don't think the US would try to sieze shipments being made by another country, say by shooting down a Chinese or Indian air force plane. That will have major consequences, and be treated an act of war.