Yellow ducky. I see that you are being reasonable and trying to make a military presence seem impossible. The fact is that the military technology available to powerful nations is beyond most civilians' comprehension. It would be quite easy for the U.S. and other powers to put a stop to this piracy. I think the issue is that there is a lack of will to do so. There surely is no lack of means, military satellite imagery can pinpoint a
dinghy nearly anywhere on the globe at nearly any time. The U.S. military is larger than many nations, and has a huge economy wrapped up with it. With a handful of aircraft, satellite surveillance and some solid naval strategy, the pirates would be history in a few minutes. The whole thing could be acheived with a small number of men. The problem is that large nations don't really care. There is no benefit to the United States seen by stopping these pirates. They are less of a hazard to commercial shipping than weather, they are basically petty in the eyes of a large nation, and they don't offer anything as a prize for their extermination. In short, pirates are to militaries as fruit flies are to a restaurant staff. Sure they are annoying, but it wouldn't be difficult to exterminate them, it's just that there are bigger fish to fry.
If I were to sail through pirate alley... well, I hope you have seen the anti-theft flamethrowers on cars.
