If the US does not project a global military presence on "the high seas" international trade will stop due to piracy in key places. It's really that simple. Singapore and the Suez Channel will become effectively unpassable unless you buy of 30 different military forces or shoot your way through.
Immediate consequence : availability of oil throughout 90%+ of the globe drops to 5-10% of what it was before in Europe, 40-50% of what it was in the US. In other places it'll be worse. Slightly longer term consequence : it becomes impossible to produce electronics.
This is assuming no-one else replaces the US doing this. But, who CAN do this ? China might be able to, but I don't think USians will like the consequences of that (e.g. their territorial expansion project ... their attitude to what happens to basic resources ...)
What are you talking about? The US Military does not enforce free trade on the high seas. I am not aware of it taking any day to day role against piracy at all.
Singapore has its own navy. Why would you need to buy off 30 different military forces to sail the straits of Malacca? I'm not an expert on Egypt but I'm sure they can enforce free passage on their own canal.
You're talking as if the US is the only rational state actor in the world. It is not. This is not The Pirates of the Caribbean, and the US is not the British Empire circa 18th century.
Immediate consequence : availability of oil throughout 90%+ of the globe drops to 5-10% of what it was before in Europe, 40-50% of what it was in the US. In other places it'll be worse. Slightly longer term consequence : it becomes impossible to produce electronics.
This is assuming no-one else replaces the US doing this. But, who CAN do this ? China might be able to, but I don't think USians will like the consequences of that (e.g. their territorial expansion project ... their attitude to what happens to basic resources ...)