Imagine what would be said if President George Bush nominated John Bolton to be his ambassador at Nato. Not that there is anything wrong with Bolton from a professional or intellectual point of view. You may disagree with his hardline neocon views, which come across as scary and warmongering, but at least he is not afraid of speaking his mind and is not for turning. With Bolton what you see is what you get and there are no surprises.

A similar scenario saw eyebrows being raised in the diplomatic community last week, when President Vladimir Putin appointed his old chum Dmitry Rogozin to be Russia's permanent representative to Nato. Described as a firebrand nationalist by those who know him in Moscow, Rogozin is in fact a seasoned campaigner with a solid pedigree, having studied journalism at Moscow State University before entering politics to head up the Kremlin-backed Motherland Party.

But just as Bolton brought unwanted baggage with him when Bush appointed him US ambassador to the UN, so too does Rogozin go to Nato with a preconceived agenda. He's no friend of the north Atlantic alliance and like Putin he views with deep suspicion its expansion eastwards into the countries of the former Warsaw Pact. Where Western leaders see an opportunity to end centuries of European wars by bringing stability from the Atlantic to the Urals, many Russians only see an unwarranted imposition on their own doorstep. "Colonial" was the word that Rogozin used.

Already we have a pretty clear idea of what kind of stance he will take when he takes up his post in the spring. Moscow's new permanent representative is not going to be a mere watchdog that gives the occasional warning bark. He will not be slow to bare his teeth and that could signal trouble ahead for the rest of the pack. On the question of the future status of Kosovo, which is still waiting resolution, he has said he will fight to protect the interests of the Serbs - as ever (shades of 1914), Russia regards herself as protector of the Slavs - and he will not sit and twiddle his thumbs if he thinks Belgrade's best interests are being damaged.

As the province intends declaring independence next month and will be supported by the US, Britain, France and Italy, there could be an immediate flashpoint as Western diplomats have made it clear they will counter Slavonic opposition by attempting to draw Serbia into the European Union and later into Nato. Incendiary ideas of that kind will only reinforce Rogozin's belief that the Western alliance is becoming over-mighty in its approach and that his own country is being challenged by what he describes as unnecessary "muscle-flexing".

It's not difficult to see why he feels that way. Nato is now the dominant European alliance and it will add to its military strength when it adds Bush's missile defence shield to its arsenal. This is another sore point. The US regards the system as a necessary means of protecting itself and its allies against any nuclear threat, especially one posed by rogue states. The Russians, meanwhile, have attacked it as an uncalled-for provocation that will upset the balance of power and threaten Russia's own hopes of becoming a world super power.

And more than anything else that's Russia's biggest beef. Since the end of the cold war it has seen its authority belittled by the dismantling of its empire as one after another former colony in the Warsaw Pact - notably Hungary and Poland - has embraced the West, leaving the Russians angry and resentful.

For a while, the new settlement didn't really threaten the world order, as Russia remained a ramshackle edifice with a chaotic economy that was more Wild West than Wall Street. Then came Putin and the new oil wealth and now Russia is not just on the road to recovery, it has almost reached its long-anticipated destination as a country that can once again rival the United States.

Things came to a head last summer when Putin placed a moratorium on the Treaty on Conventional Armed Forces in Europe, a bellicose move that raised the spectre of a return to cold war confrontation. His allies in the military want to take several steps further forward and use the revived economy to rebuild Russia's largely obsolescent arsenal. In real terms, that means more expenditure on the military, greater investment in technology and the purchase of shiny new weapons systems.

And guess what? That's just what Rogozin wants too. When he pitches up in Brussels, Nato will have a pretty good idea of what kind of guy is coming their way: an old-fashioned bear who told his supporters last week that "at this crucial moment for our fatherland patriots cannot stand aside".