Russia For Now Holds Its Trump Card

President Putin's reprisal today was measured. (Video) He shrewdly held out his ultimate card -- energy -- as ammunition to be used as he believes the need arises.

For his domestic audience, Putin could have done no less than the expulsion of an equal number of British diplomats, and possibly also the imposition of visa restrictions that was announced. The moratorium on terror cooperation can be taken with a grain of salt -- the two sides share concern on the important grounds, and joint efforts will continue.

As noted in a comment to the previous post, Russia and Britain to a degree are tied at the waist financially -- BP for instance desperately needs continued good relations with Moscow for its current and future production and reserve base. But Russian business relies on London's capital markets as well.

Concern about Russia's future attitude toward British business is well-founded. That remains the likeliest ground for Putin's long-term reaction to what, if one listens to his remarks, he seems to regard as an intolerable challenge to Russia's image and its law. BP's investments remain Britain's soft underbelly.