I heard on the news that these merchant ships are not properly armed because the shipping companies cut corners where they can. Apparently it costs LESS to pay ransoms.
There is a simple way of dealing with that. Allow the crew to arm themselves as they please. I'm willing to bet that most American crew aboard cargo ships would be willing (and happy) to pay for and bring their own firearms aboard if allowed to do so. There's no need for the shipping companies themselves to pay money to arm them.