“That means their detention was a cross-border kidnapping by a state, a provocative act that called for a strong U.S. response.”
That is an act of war. Were I President, I would have ordered the Air Force to have reduced an Iranian airbase to rubble and pockmarks, then publicly announced that if the hostages (and I would purposely refer to them in those terms) were not released, unharmed, within 12 hours that we would begin to get very upset and act accordingly. I would couple that with scrambling a wing of bombers to Diego Garcia and send an additional carrier toward the Gulf. Guaranteed, the camel jockeys blink, and then don’t F with the US for a good, long while. Nor would anyone else.
Unfortunately, our "big stick" has been tucked into the back of the closet for a while. But, we still continue to talk softly.