Moscow warned the West against supporting Georgia’s leadership and called for an arms embargo against the ex-Soviet republic until a different government is in place. Georgia was part of Russia formally U.S.S.R. which collapse in 1991 by western conspiracy and used Pakistan and Afghanistan as its allies. Moscow exasperated because first US & EU had accused him of using disproportionate force and of violating the terms of a ceasefire that called for the sides to withdraw their forces to pre-conflict positions. Where as frictions between Georgia and South Ossetia, which has declared de facto independence since Soviet collapse, but intensified when Mr. Saakashvili came to power in Georgia and made national unification a centerpiece of his agenda. Mr. Saakashvili, a close American ally who has sought NATO membership for Georgia, is loathed at the Kremlin in part because he had positioned himself as a spoke’s man for democracy movements and alignment with the West.

The escalation risked igniting a renewed and sustained conflict in the Caucasus region, an important conduit for the flow of oil from the Caspian Sea to world markets and an area where conflict has flared for years along Russia’s borders, most recently in Chechnya. The military incursion into Georgia marked a fresh sign of Kremlin confidence and resolve, and also provided a test of the capacities of the Russian military, which Mr. Putin had tried to modernize and re-equip during his two presidential terms.

Now Moscow conducted air strikes on Georgian targets on last Friday evening, escalating the conflict in a separatist area of Georgia that is shaping into a test of the power and military reach of an emboldened Kremlin. Earlier in the day, Russian troops and armored vehicles had rolled into South Ossetia, supporting the breakaway region in its bitter conflict with Georgia.

The war between Georgia and South Ossetia, until recently labeled a “frozen conflict,” stretches back to the early 1990s, when South Ossetia and another separatist region, Abkhazia, gained de facto independence from Georgia after the collapse of the Soviet Union. The region settled into a tenuous peace monitored by Russian peacekeepers, but frictions with Georgia increased sharply in 2004, when Mr. Saakashvili was elected.

If instead of choosing their national interests and the interests of the Georgian people, the United States and its allies choose the Saakashvili regime, this will be a mistake of truly historic proportions. For a start, it would be right to impose an embargo on weapons to this regime, until different authorities turn Georgia a normal state. Today’s EU summit would clear up a great deal. We hope the choice they make will be based on Europe’s fundamental interests. Russia’s relations with Nato are facing a “Moment of trust”.