At this point though, it isn't happening. The dollar is still the unit of exchange for most countries (but I don't think it will be for long). Russia and China are already moving away from it.
Bitcoin's market cap isn't big enough to be a factor in world trade. It's only about $41 billion, whereas physical money is $31 trillion. So there's plenty of room to grow. This means that it cannot influence world trade, but it might be able to in the future. It is a useful enough tool, so more and more countries will want to start using it.
First of all the market cap of bitcoin is 104 billion dollars and not 41 billion, but I agree with the rest of the post, the US thinks they can print the US dollar with impunity and now we are seeing some countries trying to get away from it, at least in some of their transactions, but the US dollar still is the king due to the size of the US economy but when an economic crisis strikes that could be a blow to the size of the economy of the US and it could be enough to shake the confidence in the US dollar to the point it is abandoned as the reserve currency of the world.