No sooner had the heads of the G7 leading nations issued a statement yesterday condemning Russia for fomenting trouble in eastern Ukraine than pro-Russian militias kidnapped eight international observers. The statement was, as required by diplomatic protocol, "strongly worded". It said the G7 leaders "have now agreed that we will move swiftly to impose additional sanctions on Russia". But the response of the gunmen on the ground seems to illustrate the ineffectiveness of sanctions.
We should, however, be clear. Sanctions could bring pressure to bear on Vladimir Putin, the Russian President; they should be made more stringent; but there is a limit to what the United States and the European Union, as the other guarantors of Ukrainian independence and territorial integrity apart from Russia, can achieve.
The travel bans and minor irritations imposed on Russia so far are weaker than they could have been, for good and bad reasons. The good – or at least pragmatic – reason is that so much of the EU, including Germany, is dependent on Russian gas. There has been talk of the US diverting some of its bonanza of shale gas to Europe to reduce this dependence, but so far this has been neither practical nor affordable.
The cowardly reason is that governments, including our own, have been sensitive to business lobbying. This was revealed when yet another document was caught on camera by a photographer, as an official walked up Downing Street last month. It suggested that the UK should "not support, for now, trade sanctions … or close London's financial centre to Russians".
This was a mistake. It was notable that yesterday's G7 statement did not specify what "additional sanctions" would be imposed. When EU diplomats meet tomorrow, they should reconsider that omission. It is, of course, not mere cowardice that has prompted EU governments to hold back from tougher measures. There is a principled, if slightly cynical, argument that Mr Putin is doing so much damage to Russian economic interests by his nationalist adventurism that he needs no help from us to make it worse. Indeed, if trade and financial sanctions were imposed, it would allow Mr Putin to blame "the West" for Russia's hardship rather than his own folly.
It is certainly the case that Mr Putin might be biting off more than he can chew and that if he tries to assimilate populations into Russia who do not want to be assimilated he will only add to Moscow's problems and costs. Crimea was one thing. We should not accept its annexation, but its population is mostly Russian. Eastern Ukraine is entirely another matter and it is quite against Russia's interest to incite separatism there.
Thus the cynic would quote Napoleon and say that the US and EU should not interrupt their enemy when he is making a mistake. The markets have already marked Russia's credit rating down to just above junk status. So far, Mr Putin's assertion of Russian power has won him the support of Russian public opinion, but this may change as the bills begin to come in.
However, the idea that Britain, the EU and the US should hold back for fear that Mr Putin would blame us fails to persuade. His rhetoric is already turned up to the anti-Western maximum, blaming the fall of Ukraine's government on US- and Nato-backed "fascist elements".
Sanctions do not always work. But they can work, and there is no other option open to those who support Ukraine's independence and integrity. Economic pressure is the best hope of bringing Mr Putin to his senses and there is no good reason, now that his proxies have started taking international observers hostage, to hold back from adding to that pressure.