While declaring "We would not be in favor of a preemptive strike on Iran," UK defense secretary Philip Hammond vowed that any attempt to disrupt the flow of oil through the Strait of Hormuz "would be illegal and unsuccessful."

Speaking at the Atlantic Council on NATO and the Case for Collective Defense in the 21st Century, Hammond reinforced transatlantic doctrine dating back to the Carter administration when he stated, "It is in all our interests that the arteries of global trade are kept free, open and running. Disruption to the flow of oil through the Strait of Hormuz would threaten regional and global economic growth."

So, while his government would prefer to avoid the use of force, it would use it if necessary.

He observed, "Our joint naval presence in the Arabian Gulf, something our regional partners appreciate, is key to keeping the Strait of Hormuz open for international trade" and added, "The Royal Navy will continue to play a substantial role as part of the Combined Maritime Forces, both at the headquarters in Bahrain, and through our mine counter-measure vessels which help maintain freedom of navigation in the Gulf."

Of course, the reason Iran is threatening to close off the Strait of Hormuz is because the regime is feeling squeezed by tightening US and European sanctions in response to intransigence on its nuclear program. Asked about that in Q&A, Hammond was blunt: "My working assumption is that they are working flat out" on building a nuclear weapon. 

More generally, Hammond says that his government has "a strategy of pressure and engagement with Iran." This, of course, was the Obama administration’s approach in its early days in office. More recently, they’ve largely—and quite reasonably—put the engagement half of that on the back burner.

It would seem obviously in the interests of all concerned to avoid war in Iran. Despite a lot of saber rattling and talk about a nuclear Iran being "unacceptable," the military option has been only theoretically on the table during the years of tensions over the issue.  

One hopes that the Iranian regime receives Hammond’s message that this forbearance has its limits. A standoff over the Strait of Hormuz would almost certainly lead to shots being fired. Containment becomes quite difficult, indeed, once that happens.

James Joyner is managing editor of the Atlantic Council.