Twenty years after the end of the Cold War, we face a new challenge: how to conserve liberal freedoms once our citizens feel safe enough to take them for granted. Totalitarianism of the left and right, which defined liberalism throughout the 20th century, is no longer there to remind us how precious freedom is. It is up to us all to remember who we are, why liberty matters, why it is a discipline worth keeping to, even when our own sinews tell us to relax.

Today, liberal democracy’s decisive encounter is with post-communist oligarchies – Russia and China – that have no ideology other than enrichment and are recalcitrant to the global order. Predatory on their own societies, Russia and China depend for their stability, not on institutions, since there are none that are independent of the ruling elite, but on growth itself, on the capacity of the economic machine to distribute enough riches to enough people. They are regimes whose legitimacy is akin to that of a bicyclist on a bicycle. As long as they keep pedaling, they keep moving; if they stop, they fall off.

Both Russia and China are attempting to demonstrate a novel proposition: that economic freedoms can be severed from political and civil freedom, and that freedom is divisible.

The liberal democratic creed is that freedom is indivisible. What this means is the interdependence of political and economic liberty, the interdependence of majority rule and minority rights, the interconnection between rule of law and democratic sovereignty.

Yet our fascination with the economic rise of China, fueled by cheap labor supply chains in global manufacturing and the steady growth of a domestic consumer market measured in the hundreds of millions, often leads us to forget that the new Russia poses an equal strategic challenge to this belief – and thus to the very shape of the 21st century.

The Putin regime is something unprecedented in the annals of political science: a tyranny that ratifies itself with rigged elections; a market society in which everything is for sale, but no one’s property is safe; a petro-state that leaves millions so poor they remember Soviet times with nostalgia; a state ruled by a former secret police agent whose only contact with a liberal Western state was as a spy and whose understanding of power was learned in the interrogation rooms of a police state.

Putin does not express explicit designs on territory or freedom; he offers no ideology for export, no radiant tomorrow, no goal other than power for himself; but all the same, he is not happy and because he is not happy, we are not secure. He knows that millions of his citizens no longer thank him for the security his regime has provided. They have tasted some freedom, and they both resent his authoritarianism and worry that their own economic freedoms are insecure under his rule.

Russia’s wealth is precarious. Its natural-resource income leaves the regime dependent upon the ups and downs of the commodity price cycle. Under Putin, it has become a petro-state vulnerable to Dutch disease, corruption and increasing inequality; its political order is entirely without checks and balances, without the rule of law, and without even an orderly democratic mechanism for leadership transition.

In both Russia and China, rising real incomes have replaced ideology as the key to post-communist legitimacy. Yet wealth is an unstable source of legitimacy. Since both regimes are predatory, wealth is highly concentrated in those with access to power. The strategic question is whether Russia and China are stable. Ostentatious wealth, built on corruption, power concentrated in few hands and unconstrained by institutions, is not a recipe for stability at home or peaceful relations abroad.

Both China and Russia are societies in which power is stacked: political power confers economic, social and cultural power. They remain single-party states, emptied of the ideology of communism, yet imbued with the same Leninist attitude to power. Leninism dies hard, but sheer ruthlessness is a brittle basis for legitimacy.

If liberal democracy is premised on the idea that freedom to own and acquire presupposes and requires the freedom to act, to believe and to know, the liberal ideal also presupposes that the truth is one, can be known and can be shared. Legitimate regimes are regimes that face facts. Regimes become illegitimate when they deny important facts staring them in the face.

Russia and China have quietly put communism aside as a public belief system, but they have never faced up to Communist legacies of terror, starvation and persecution. In both societies, there remains a lurking nostalgia for terror. Mao continues to glower down over Tiananmen Square. Uncle Joe’s picture is still carried in parades in Moscow.

So a critical question for liberal society becomes how do we define ourselves in relation to these new forms of domination – Russian and Chinese – how do we understand them and live in peace beside them?

We should be asking this question, but instead we leave the answer to commerce and capitalism, trusting that as we create contracts and economic relationships, the fundamental question of how liberal societies should relate to non-liberal ones will resolve itself. The invisible hand will do its work, and if power passes to Moscow and Beijing, so be it.

Cold War liberals, like the philosopher Isaiah Berlin, thought differently. They thought that the question of how liberal societies should relate to non-liberal powers could not be left to fate and the global division of labor, but was a political, strategic, and moral issue to be decided by democratic peoples.

Isaiah Berlin did not live to see these new tyrannies arise in Russia and China, and he would have trouble recognizing the world we now inhabit – post 9/11, post-meltdown, post-liberal in so many ways – but he did know a lot about living beside barbarians. His Cold War liberalism has much to teach us still.

The first lesson, as the 19th century Russian writer Alexander Herzen said and Berlin liked to repeat, is that history has no libretto. We should not assume there is any historical inevitability to liberal society, anymore than it made sense to predict in 1950, say, that both Chinese and Russian totalitarianism were doomed to crumble. Since no one predicted the direction these societies have taken, no one can be sure that either will evolve toward anything remotely like a liberal democratic order.

To say that history has no libretto is not a counsel of pessimism. Berlin’s historical humility was always paired with a strong belief in the efficacy of freedom. Leadership, he knew, could bend the arc of history, if not always toward justice, at least away from tyranny.

If this is true, then in our dealings with the Chinese and Russians, it matters to give help to those who campaign for the rule of law, not the rule of men, who want poor villagers to be fairly compensated for expropriations of their land, who want ordinary people to have the right to read anything they want on the Internet, who want free and fair elections and an end to the rule of billionaire oligarchs.

History is not necessarily on the side of these liberal values, but fighting for them remains a moral duty. We do this because history is on nobody’s side, and freedom needs all the help it can get.

If this seems a defiant stance toward the new tyrannies in China and Russia, and it is, then we need to learn from Berlin how to balance resolution toward tyranny with openness toward what these societies can teach us. This balance between firmness and openness is the equilibrium the liberal temperament is always seeking and a liberal foreign policy should always aim for.

While liberal tolerance can look a lot like appeasement, Berlin shows us how it is possible to combine tolerance with firmness. The true pairing of tolerance should be with curiosity, with an appetite to learn from beliefs we cannot share.

The larger point is that Berlin thought it was dangerous to organize one’s mind into fixed and immovable categories of “us” and “them”, still worse to believe that without a “them” there can be no “us”.

Liberals refuse to treat opponents as enemies. They see their antagonists differently, as persons who must sometimes be opposed, and with force if necessary, but also as persons who might be persuaded to change their minds, and who, in any case, must be lived with, if they cannot be changed.

In the domestic politics of liberal societies, we need to maintain this distinction between opponent and enemy. Democracy cannot function without opposition, and the opposition must be given the presumption of loyalty.

Likewise, on the international stage, observing the distinction between enemies and opponents is vital in any situation short of actual war. In war, we have enemies. Short of war, they are opponents, and we are in the domain of politics, that is to say, in the domain of negotiation, bargaining, compromise, and where compromise is impossible, “agreeing to disagree”.

What Berlin’s Cold War liberalism has to teach us is that in international relations with opponents we should practice politics, not war, politics, not religion.

Nothing is gained by pretending that Russia and China are not the chief strategic threat to the moral and political commitments of liberal democracies. We should understand this threat for what it is. We are faced with political opponents, and if our belief in freedom is grounded in the facts, we will win.

This is adapted from the Isaiah Berlin Riga Memorial Lecture, delivered by the author last month.

PHOTO: China’s President Hu Jintao (R) and Russia’s President Vladimir Putin (2nd L) attend a signing ceremony at the Shanghai Cooperation Organization (SCO) summit in the Great Hall of the People in Beijing, June 7, 2012. REUTERS/Mark Ralston/Pool