While the world has been avidly observing Russia’s massing of troops near the Ukrainian border, a major political event has passed by relatively unnoticed. This was Russia’s quiet declaration in November — at the beginning of its current military build-up — that it had signed a new security doctrine with neighboring Belarus.

This may seem unimportant relative to the developing situation in Ukraine, but it is no less significant. In fact, this new stage of their security relationship may have far greater implications for NATO than the current tensions.

President Vladimir Putin and his Belarusian counterpart Aliaksandr Lukashenka are uncomfortable bedfellows. Their animosity is well documented — Belarus went so far as to criticize Russia’s annexation of Crimea in 2014, and has played host to the eponymous Minsk agreements. The passing years have seen one spat after another, including over Russia’s raising of oil taxes in 2019 and the recall of Russia’s ambassador to Belarus that same year over his controversial attempts to play a greater role in domestic politics. Events culminated in the Belarusian security services’ violent response to August 2020 protests against Lukashenka’s re-election, in a vote widely viewed as rigged. In this instance, the Russian security forces — while briefly assembled on the border — did not intervene, and appeared to be hedging their bets on whether the demonstrations would topple Lukashenka, leaving them to broker ties with a possible new administration.

But once Lukashenka’s survival was assured, Russia resumed the promotion of the Union State’s importance with greater urgency. This framework agreement was first signed in 1999, but meant little formal integration in practice. One of the telling signs that Russia was prepared to take this seriously was the promotion in March 2021 of Dmitry Mezentsev to Secretary of the Union State. Mezentsev was formerly Russia’s ambassador to Belarus — whose aforementioned predecessor was recalled — and had been a safe pair of hands in navigating their difficult diplomatic relationship.

For years, Lukashenka had resisted deeper integration, periodically accusing Moscow of threatening Belarus’s national security. Indeed, one of the main sticking points was Lukashenka’s refusal to permit the installation of a Russian airbase on Belarusian territory, citing Belarus’s stated neutrality. But this has changed.

Weakened by renewed Western hostility and sanctions, a new and fundamental reliance on Russian financial assistance with a resultant inability to play Russia off against the West, Lukashenka’s resistance began to crumble. A flurry of meetings with Putin ensued throughout last year, and Lukashenka’s rhetoric began to evolve. In September, prime ministers from the two countries signed a Union State resolution to formally agree to 28 programs on economic integration; establishing a unified gas market, and discussions about a single defense space. Then in November, Lukashenka abruptly maintained in a prime-time Russian TV interview that he did recognize the Crimea annexation after all, running counter to his long-standing position.

Putin and Lukashenka were said to have signed the new security doctrine as early as November, but no details were made public. Only in February were the contents of the document published on the website of the Standing Committee for the Union State.

Meanwhile, Belarus published proposed constitutional amendments, which are likely to be formally approved in a referendum on February 27. There were two significant elements in the amendments. The first was political — plans to further weaken Belarus’s rubber-stamp parliament and introduce changes that allow Lukashenka to remain in office until 2035. This ensures no leadership challenges and no fundamental changes to Belarus’s political or security trajectory.

But the second and more serious change was an amendment removing Belarus’s commitment to be neutral and free of nuclear weapons. Previous versions of the constitution refer to Belarus’s commitment to nuclear-free status, but amendments to Article 18 deleted this text, maintaining that it will not allow military aggression against other states to be launched from its territory. Purposefully vague and with no further details, this could mean that Belarus would not allow Russia to militarily intervene in Ukraine via its military presence in Belarus. Or maybe not, since Lukashenka has echoed every Kremlin sentiment through the crisis and has — after all — done an abrupt about-face on his previously staunch commitment to neutrality. While NATO concerns chiefly center around whether Russia and Belarus’s Allied Resolve exercises will be a means for Russia to maintain troops in Belarus, these amendments would allow Russian nuclear infrastructure on Belarusian territory, a fundamental change, and a significant strategic challenge.

Russia often frames its own foreign policy as reactive, particularly to NATO and US policymaking; the security document specifically mentions NATO’s presence in Ukraine as a contributing factor to establishing the joint doctrine. Earlier in December, Russia’s deputy Foreign Minister Andrei Rudenko maintained that Russia would consider basing nuclear weapons in Belarus if Ukraine were given NATO membership, or if additional weapons were moved to the Baltic states. Russia has repeatedly asserted that it views NATO’s Aegis Ashore anti-missile sites in Romania and Poland as a security risk, and views this latest nuclear alliance as a counterpoint.

Known for his blustery rhetoric, Lukashenka is already embracing the change. On February 17, when referring to the Ukraine situation, he threatened the West with nuclear weapons to protect Belarusian territory, in the event of an escalation.

Russia is much more circumspect. It is likely using this alliance with Belarus to highlight its military cooperation with close allies; showcase its ability to move nuclear infrastructure close to the Baltic states’ borders, and to counter what Russia views as a lack of parity in Europe. But this move could also reflect Russia’s own lack of understanding about NATO’s intentions. Far from a display of confidence, it suggests that Russia is misreading the West, which could have dangerous implications for escalation in Europe.

Emily Ferris is a Research Fellow at the Royal United Services Institute (RUSI) in London, specializing in Russia and Eurasia’s foreign policy. Emily has a particular interest in Russian organized crime and Russian foreign policy. Before joining RUSI in 2018, Emily worked at Control Risks.