There will be furious embarrassment in the British government this evening over Iran's seizure of two British oil tankers today. One of those tankers is British-flagged, and the other is British-owned.

Still, Iran has made a strategic miscalculation here.

Acting against the British while the U.K. and Iranian foreign ministers were seeking compromise over Britain's recent seizure of an Iranian tanker, the Islamic Revolutionary Guard Corps have further isolated Iran on the international stage. With a multinational naval task force for tanker escorts likely to be announced next week, the Iranians are increasingly outgunned and diplomatically isolated. Losing a drone to a U.S. warship on Thursday, the Islamic Revolutionary Guard Corps is also now aware of American red lines against threats to U.S. life.

But none of that will distract from London's embarrassment.

Britain was well aware that this kind of Iranian aggression was likely. Deploying an advanced warship to the Persian Gulf, the U.K. expected to deter Iran. That calculation has clearly failed in quite spectacular fashion. The military options to retake these tankers are also weak. While Britain's Special Boat Service special forces unit has an advanced maritime counter-terrorism capability, recovering tankers now in Islamic Revolutionary Guard Corps port would be an extraordinary challenge.

That said, Iran's action here presents two problems for Tehran.

First, it will encourage Britain to support the U.S. sanctions pressure campaign against Iran. With a new British prime minister entering office next week, the U.K. will want to regain the initiative here against appearing weak. But Iran's action also makes it likelier that France and Germany will adopt a tougher stance against it. Those nations have pursued an appeasement strategy until now, but they will view Iran's escalated endangerment of global energy supplies as intolerable.

Ultimately, then, Iran is heading for more economic damage. These seizures might make the hard-liners feel good, but they've made a big mistake.