Every article I read about the navy destroying a ship, the article refers to them as 'suspected drug smugglers'. In no instance have I read that an armed boarding party was sent to the ship to inspect the cargo. I think that falls into the same category as 'he's black, must be a gang banger'.
They may have intelligence leading them to suspect a specific ship is a drug runner, but without actual proof, destroying the ship and killing the crew is an act of piracy and murder.
Yes, boarding the ship does expose the crew to risk. It is the same sort of risk every cop is exposed to when they break down a suspected drug dealer's door. If the police, who don't have cannons backing them up can do it the right way, so can the navy.
The military has rules of engagement. I was in the army, not the navy, but I suspect that "there's a boatload of brown people they must be guilty of something" doesn't meet the criteria. Of course the draft dodger in chief wouldn't know anything about that.
Using the navy to interdict drug trafficking is not in and of itself a bad idea. By all means board suspected ships, and arrest the crew members if they find contraband. Those ships found to be carrying illegal drugs should be confiscated and sold, not sunk, with the government retaining the proceeds.
And the drugs? Those are the evidence to be presented in a US court, after which they can be destroyed.
