Only the most gloomy pessimists think Russian President Vladimir Putin will launch a military invasion of Ukraine to bring it back into Moscow's fold. But even the most cheerful optimists can envisage no scenario that does not leave Ukraine crippled, destabilized and a constant hostage to the Kremlin.

A highly dangerous week lies ahead. The Ukraine government in Kiev is preparing military operations to recover control of public buildings in the eastern part of the country that have been violently seized and occupied by pro-Russian forces. Shots have been exchanged, at least one Ukrainian officer has been killed.

The Russian government insists it stands ready to intervene to protect the interests of ethnic Russians against what it calls "fascist gangs" of Ukraine nationalists. It has 40,000 Russian troops poised on the border to carry out the threat.

The United States made it clear, at the United Nations security council meeting Sunday, that it simply does not believe Moscow's claims that these pro-Russian forces have emerged spontaneously and acted of their own accord. It sees the same Machiavellian strategy at work that took back Crimea, with Russian agents fomenting unrest, deploying Russian troops with identification badges removed, playing the part of local militants as they pave the way for a Russian take-over.

"This is the saddest kind of instability: it is completely man-made," said Samantha Power, the U.S. ambassador to the UN. "This 'instability' was written and choreographed in and by Russia. These are not protests; they are military operations."

We have seen these tactics before, in Georgia, in Crimea and now in Ukraine. The echoes of the 1930s, when Hitler marched into the demilitarized Rhineland in 1936, took over Austria in March, 1938, and in September of that year launched the Munich crisis that won him the Sudeten region of Czechoslovakia. And in March of the following year, he took over the rest.

Then as now, the Western democracies were slow to believe that the ordered world of diplomacy and the League of Nations was being disrupted by an authoritarian leader whose ambitions knew no bounds. Still today, arguments can be heard in defense of Putin's policies.

It was foolish of NATO to expand into Europe and up to Russia's borders, it is said. Perhaps, but NATO is an organization based on the free decisions of democratic states. When counties like Poland and the Baltic states freely elected governments who sincerely wanted to join NATO, how could they honorably be refused?

Georgia, Crimea and Ukraine have "always been in the Russian sphere of interest," it is said. But so have the Baltic states and Poland, and it was to make sure that never happened again that they chose to join NATO. Ukraine is not about to join NATO; what it seeks is eventual membership of the European Union, which is hardly militarily provocative.

European foreign ministers, meeting Monday, are supposed to consider much tougher sanctions to be imposed against Russia if Putin's salami tactics continue. But the list of options for sanctions being drafted by the European Commission is not yet ready, so once again the Europeans have an excuse to kick the can a little farther the road as they mull over Putin's threats to turn off their gas supply.

So far only three EU countries, Sweden, Lithuania and Luxembourg, have backed Ukraine's right to use force to re-assert its sovereignty over eastern Ukraine. Britain and France have talked tough. Everything rests with Germany, where opinion polls suggest only a minority support sanctions against Russia, after industrial spokesmen claimed that 300,000 german jobs depend on exporting to Russia. And the highly respected former German Chancellor Helmut Schmidt has argued that Putin's actions were "understandable" and that sanctions were "nonsense."

German foreign minister Frank-Walter Steinmeier is pinning his hopes on a scheduled meeting in Geneva Thursday, in which the U.S. and EU will try to get Russian and Ukrainian officials to reach some form of accord. The situation in Ukraine is "not only explosive. It is high-risk", he said on German TV Sunday. "The situation is so tense that those who have responsibility in East and West must now come together to prevent worse."

He has a point, just as British premier Neville Chamberlain had a point at Munich in 1938, when he believed some sort of agreement that could "prevent worse" was worth the sacrifice of Czechoslovakia. But at least Chamberlain was using the time he bought to re-arm and to prepare for the worst if it came. So far, there is little sign that the Europeans are being serious about their defenses or even their ability to reduce their dependence on Russian energy exports.

The ultimate question is where Putin will stop. After Ukraine, he may be tempted to try his well-honed destabilization tactics in Estonia, Lithuania and Latvia, three former Soviet republics which are now full members of both the EU and NATO.

Those memberships ought to be a very firm red line for the U.S. and Europe alike. But Putin knows from Syria how much credence to place in "red lines" as sketched by the current White House.