But hey, Pirates, harr!
EDIT: Now that I think of it, any prospective privateer is facing a couple of challenges (privateering is business after all): If you operate under an US Letter of Marque you have a limited number of prizes. Those prizes are comparatively easy to capture, legitimacy isn't your immediate concern and selling the prizes is a solved problem.
If you operate for the Russians, potential prizes are plenty. Legitimacy is a major concern, so. As is selling those prizes for money. Capturing a container ship is easy (just ask the Somalis), piloting it to a friendly port as well, crews are really small nowadays. Selling 10k TEU is a different story so, especially if the party issuing your Letter of Marque is short on hard currency. And has a limited number of deep sea ports. Those ports are, lucky for any potential privateer, close to the largest ports of origin in the Pacific. One just has to be careful to not piss of the Chinese. resorting to Letters of marque could turn the Pacific into a, almost, hot war zone resembling the Caribbean during the golden age of piracy.
Unlikely scenario, but stranger things have happened. It would make a great military fiction novel so!
Nothing except the US Navy patrolling shipping lanes, as they already do.
If Russian had a global navy they might have a stronger position. But as it is now, pirates will never encounter a Russian ship. They will likely encounter a US ship, especially if they try to disrupt that tanker full of Cheetos (or whatever).
If anything, the Russians could benefit most from a full-blown privateering program.
Privacy still exists [0] with more in the Straits of Malacca than off Somalia.
This piracy is much less due to the actions of the US Navy. I’m not sure why you think it would increase 10x if Russia endorsed privateering.
I think Russia’s position is moot since their fleet would never stop this in the first place. So their privateering position doesn’t seem to matter. While there’s lots more US (and US-bound) ships, I don’t think Russia’s navy is preventing any piracy.
[0] https://en.wikipedia.org/wiki/Piracy_in_the_21st_century