Eurasianism, as an ideology, has defined itself against Atlanticism. But the reality may turn out different, as Russia's practical Eurasian role gets separated from the ideology some have tried to build around it.
If we ask which geographical identity captures Russia's essence, we have many options: European, Eurasian, or Western (Atlantic) to start with; then also, it could be uniquely Russian, or universally human.
In ideological discussion, the five options are usually counterposed, which makes for spectacular debating fireworks. But the actuality is that Russia is all of them; the only real question is the degree and manner of combination.
That question, to be sure, is extremely important. Russia's choice of priorities and preferences among the options plays a vital role in shaping how Russia behaves in the world.
While any attempt to define Russia by an exclusive geographical term and to separate Russia from the other geographical identities is, as I have said, doomed to failure, this does not mean that it cannot win temporary political victories. What it means, rather, is that it will self-destruct. And the more power it gains, the more it will bring down with it.
An accurate formulation for Russia's identity would be four-fold:
1. On the global scale, Russia is a part of humanity.
2. On the civilizational scale -- which is a main base for action on the global scale -- Russia is a part of the Western or Euro-Atlantic civilization.
3. On the regional scale, Russia is a European country and a Eurasian country.
4. On the national scale, it is Russian-based and multiethnic.
A healthy Russia will have all these identities -- Russian, European-Eurasian, Atlantic/Western, and universal -- in their proper place and correlation; that is, each one focused on its own level, not interjecting itself in place of the other levels. The only way for Russia to be securely Atlanticist is for its Atlantic vision to include a Eurasian regional component and support for legitimate Russian national interests. The only way for Russia to be securely Eurasian is for its global identity to be Atlanticist, i.e. a universal humanism working from the Euro-Atlantic world as its strategic base. (Atlanticism, as an "ism", is to be understood as the modern ideology of the West which takes universal human concerns as its moral point of reference and takes the Atlanticized West as its strategic base.)
If Russia were to try to choose Atlanticism at the expense of its Eurasian statehood and connections, it would only damage the interests of the Atlantic world: the West needs full Russian engagement in its present Far Eastern lands and its former Central Asian lands if it is to keep them within the European orbit. If Russia were to try to choose Eurasianism at the expense of Atlanticism, it would only damage its Eurasian interests and put at risk its Asian territories: it needs the support of the Atlantic strategic system to guarantee its Far East from reabsorption by China and to secure its Islamic underbelly. The dogmatic Eurasianists are the worst enemies of a stable Eurasian Russia.
Nevertheless, the temptation remains to counterpose the Atlantic and Eurasian orientations. It makes for easy journalism, setting up confrontations between dramatic opposing forces. It makes for easy demonization of Russia as a dangerous Eurasianist force stalking the good Atlantic world. Or for easy demonization of America as a dangerous Atlanticist force out to destroy Russia's identity and coherence.
There are, to be sure, ideologues on both sides who are genuinely opposed to one another. Eurasianism as a basis for global ideology really is opposed to Atlanticism: it defines Atlanticism as its enemy. But that flows from the mistake of making Eurasianism a basis for global ideology in the first place, or of giving it primacy in Russia's self-definition. Eurasianism is only a regional level of identity for Russians, not the national one which is Russia itself, nor even the sole regional identity since it shares that honor with Europeanism. It is the excessive pretension for Eurasianism, using it as "the" Russian identity both nationally and regionally, which is what turns it into a de facto global ideology and counterposes it to Atlanticism.
Inside Russia itself, purist Russian Atlanticists are all the time saying that any kind of Eurasianism is bad and that Russia must choose between it and the Atlantic world. Meanwhile ideological Eurasianists say the same thing in reverse -- with somewhat greater political skill, since they stand a chance to gain temporary popularity this way. The purist Russian Atlanticists are purely self-defeating in saying these things; it guarantees that they cannot hold onto power or mainstream opinion. The Eurasianists are also self-defeating, but in the long run; their overreaching serves to assure that their Eurasianism will not be a practical matter but an ideological excess that, if it were ever to come to power, would be doomed to collapse and bring Russia down with it.
What, then, is Russia? It is primarily European in its roots, ethnos, religion, culture, and sociology. No one imagines an exclusively or even primarily Asian identity for Russia; some people do imagine an exclusively European identity for it. However, there are Asian elements in the Russian population and heritage, as well as in its geography, making its "Eurasian" character inescapable and its "European" character non-exclusive. This is not a unique case; in much the same way, the European character of the United States is primary but non-exclusive, incorporating additional ethnic and cultural elements and an American not a European geographical location.