If Trump truly is a dealmaker, however, Putin will have to sacrifice some of the core policies — anti-Americanism, economic protectionism — that have facilitated his consolidation of power.

New complexities to old problems also are likely in any rapprochement with the United States, most notably in eastern Ukraine. Before Putin counts his winnings — which could be substantial — consider what the consequences of success might mean for him.

Putin has built his foreign policy around one premise: That the United States is Russia’s primary, indeed only, international rival. Every policy, every speech, every foreign meeting, every news programme revolves around this central thesis.

But what if that enemy, or at least its most extreme caricature, suddenly disappeared? Putin has nothing to replace the propaganda gusher of an arrogant, overreaching, and power-obsessed United States.

The most obvious alternative — Russian nationalism — is just too divisive in what remains a multi-ethnic, multi-religious society. Indeed, Putin recently discussed the need for a new law that addresses inter-ethnic relations.

Yet, instead of focusing on unifying national ideas, the proposed legislation will address the dull bureaucratic minutiae of Russian state-building.

Putin could also look elsewhere for adversaries — Europe, Islamic State — but they are unlikely to galvanise the Russian people to the same extent as an old superpower rivalry. Putin may soften his anti-Americanism, but, in doing so, he risks losing one of his few dependable sources of national unity.

Ironically, a decision by Trump to lift sanctions (with the European Union immediately following suit) would also throw Putin’s current economic strategy into disarray.

In response to US sanctions over Russia’s annexation of Crimea, and subsequent military engagement in eastern Ukraine, Putin imposed his own counter-sanctions, which prohibited EU and US food imports, thereby providing a huge boost to domestic producers.

Putin also embarked on a programme of import substitution that privileges and subsidises Russian manufacturers of electronic devices, software, machine equipment, pharmaceuticals, and a host of other products, in the name of economic sovereignty.

The economic rationale behind import substitution remains rather dubious, since it will result in poorer-quality, less competitive goods.

But what if Trump offers to end the sanctions in exchange for the removal of counter-sanctions and non-discriminatory access to the Russian market?

Putin would have to lift his protectionist measures, thereby exposing all those new Russian producers of cheese, software, medicine, and other products to Western competition.

Putin’s economic strategy would unravel, and he would feel the backlash from domestic manufacturers who acted on the assumption that they would enjoy state protection for years to come.

The sudden end of sanctions would throw another wrench in Putin’s plans in Ukraine. Sanctions have become inextricably linked to the Minsk Two peace process, agreed in February 2015 by the leaders of Ukraine, Russia, France, and Germany.

The Europeans insist that the sanctions stay in place until there is progress toward implementing the agreement, which requires specific actions from both Russia and Ukraine.

The Russians are responsible for overseeing the implementation of the ceasefire by the separatists, including the withdrawal of heavy weapons from the front.

The Ukrainian concessions are much more painful: Kiev must potentially recognise local elections in Donetsk and Lugansk and provide these districts with significant regional autonomy.

If, however, Trump removes sanctions before Minsk Two is fully implemented, Ukraine would have a much freer hand in dealing with the separatists.

Indeed, some Ukrainian commentators have proposed just letting the Donetsk and Lugansk regions go their own way, thereby releasing Ukraine from having to pay for the costly process of political re-integration.

Any decision by Kiev to walk away from eastern Ukraine would present Putin with a major dilemma. The Kremlin would lose leverage over Kiev, while assuming the long-term administrative and financial responsibility for governing the eastern provinces.

Rather than accommodate such a move by Kiev, Putin most likely would feel compelled to renew military pressure on Ukraine, no doubt denying that Russian troops were involved.

It may be a good bet that Trump and his realist advisers would adopt a non-interference policy in Russia’s self-declared zone of influence, but a renewed war invariably carries new risks, especially if Putin wants to conceal Moscow’s involvement from the domestic audience. So Trump’s victory potentially may pose difficult choices for Putin. The Russian president remains a flexible politician, and may gladly accept improved US-Russian relations as a necessary pause to allow his country time to recover from a devastating economic recession. Putin’s popularity, however, is directly linked to his confrontational foreign policy and protectionist measures.

Without an external enemy, Putin will have to find other means to rally support for his policies. He won’t be able to turn to any economic successes; the ministry of economic development announced, in October, that Russian living standards won’t rise until 2035.

While the Kremlin is smiling, it also has tried to lower expectations regarding what to expect from a Trump presidency.

This may be a sound negotiating tactic, but it also may indicate that Putin needs time to rearrange his priorities, especially if a deal upends the main pillars of his foreign policy, economic strategy, and base of domestic support.

William Pomeranz is the deputy director of the Kennan Institute at the Woodrow Wilson Centre for Scholars in Washington. Any opinions expressed here are his own.