What are they going to do? Open up on the boats carrying the captured Navy personnel? It looks like this was Iranian Revolutionary Guard Navy. These zealots would kill all onboard the minute any rescue was attempted, or if there was an attempt to stop those vessels. Unfortunately it becomes a diplomatic incident.
You can't tell me that they snuck up on them.
The frigate should have positioned itself between the Iranian ships and their boats that were boarding the suspected smuggler.
This is not the first time the Iranian navy has done this.
There is an easy solution to this. Blow up an oil well. Only one.
Then tell Iran, if you do not release the sailors in 24 hours, you will no longer be an oil producing country. Then blow up another oil well.