Opinión CIDOB nº 702

Putin’s ‘red line’ over Ukraine: a new test of European and transatlantic resolve

Fecha de publicación:
Agnieszka Nimark, Associate Senior Researcher, CIDOB, and visiting scholar at the Reppy Institute for Peace and Conflict Studies at Cornell University

For the second time this year, Russia has deployed a large number of troops and military hardware near the Ukrainian border, sparking fears of an invasion in Kyiv and alarming NATO and the EU. Vladimir Putin has been vocal at expressing his disapproval regarding NATO’s military support for Ukraine and rising concerns over Russia’s security interests. The U.S. and European allies decided to send a united message of support for Ukrainian sovereignty, territorial integrity and aspirations to join NATO in the future. They also warned Russia of serious consequences, including high-impact economic measures, if Putin undertook any military action against Ukraine. These steps have so far failed to defuse the crisis. The main questions thus remain: How can the Kremlin be convinced to pull back and how to prevent a military operation, if one is indeed being contemplated?


The first military buildup to the east and south of Ukraine earlier this year, was perceived as an attention-seeking exercise. However, the current buildup is sowing confusion in the West over Russian intensions and raising fears of a possibly imminent invasion. U.S. intelligence has stated that it believes Kremlin might be planning a multi-front offensive involving up to 175,000 troops as soon as early next year. While Moscow’s intentions towards Ukraine and the pro-Russian separatist region of Donbass are unclear, Vladimir Putin has been keen to express his disapproval of NATO supplying military equipment to Ukraine. He pointed out that deployment of weapons or soldiers to Ukraine would cross a ‘red line’ for Russia and trigger a strong response, including potentially mobilizing Russian missiles targeting Europe. Putin also warned against stationing in Ukraine a NATO missile defense system, similar to those in Romania and Poland. Russia regards these systems as a potential cover to deploy offensive nuclear weapons capable of reaching Moscow in minutes. NATO’s response to Russian concerns has so far been dismissive. How can we understand why Russia has chosen to raise tensions in Europe at this moment, and why is an attack appearing more likely this time than in this past spring? 

First, a number of recent policy decisions by the United States have arguably put Russia on high alert. At the beginning of Biden’s Presidency, his administration was hoping for “stable and predictable” relations with Moscow and the quick extension of New START Treaty just before its expiration on February 5th was a promising step in that direction. However, on March 1st, the Biden administration decided to send $125 million in military aid to Kyiv. The package, funded through the Ukraine Security Assistance Initiative, included two Mark VI patrol boats as well as counter-artillery radars and tactical equipment; continued support for a satellite imagery and analyses capability; and equipment to support military medical treatment and combat evacuation procedures. In May, in the wake of the first Russian military buildup near Ukraine since the annexation of Crimea in 2014, Kyiv asked the U.S. to consider deployment of air defense systems in Ukraine (including Patriot missile air defense system). In September, the House Armed Services Committee, in its markup of the fiscal 2022 defense policy bill included a request for the Pentagon to deliver a report on options for how the U.S. could help Ukraine address air and missile defense gaps. More recently, Congress released the second part of the military aid to Kyiv under the Ukraine Security Assistance Initiative.

Second, the NATO Summit in Brussels in mid-June ended with a joint communique that reaffirmed the 2008 decision that Ukraine will become a member of the alliance through a membership action plan (MAP). While no timetable was mentioned, Ukraine’s progress on adopting NATO-mandated reforms and NATO’s practical support to reform Ukraine’s defense sector became another flashpoint in NATO-Russia relations. Then, in late October, the Alliance defense ministers adopted a confidential strategy called “Concept for Defense and Deterrence in the Euro-Atlantic Area”, with an aim to prepare for a simultaneous attack in the Baltic and Black Sea regions that may include nuclear weapons, hacking of computer networks, and assault from space. Considering that the strategy should be implemented by the late 2022, if Russia really had the intention to attack Ukraine, they might be tempted to do so before NATO’s response plans are ready.

Some of the Russian concerns regarding the strengthening of the Ukrainian defense systems and their interoperability with NATO may be reasonable, and if so, need to be addressed by the Alliance. If these concerns remain ignored, Putin stated openly what is going to happen: “We would have to create a similar threat for those who are threatening us”. What Putin was most likely referring to, was Russia’s capability to deploy hypersonic cruise missiles targeting Europe. Russia’s ally, Belarusian dictator Alexander Lukashenko, said recently his country was ready to host Russian nuclear missiles, if western countries were intent on placing nuclear missiles near Russia’s border, and referenced the Ukraine-NATO air defense plan. With the demise of the 1987 Intermediate-Range Nuclear Forces (INF) Treaty after the U.S. withdrawal in 2019, Europe is now on the verge of a missile crisis. 

Apart from Russia’s defense related concerns, natural gas shortages and soaring prices in Europe might have emboldened Vladimir Putin. Since Russia supplies almost half of Europe’s gas imports, the European allies’ response to Russia’s attack on Ukraine might be limited in winter due to their dependence on Russian gas supplies. Putin can limit gas deliveries to Europe and use his position as leverage to diplomatic pressure on European leaders. Britain’s foreign secretary Liz Truss has urged NATO allies to block Russia’s new Nord Stream 2 gas pipeline warning that Moscow would exploit its position if European nations became too reliant on it for energy. 

Putin’s intentions with amassing troops near Ukraine may be unclear, but what he wants is not: Moscow wants guarantees that Ukraine would never join NATO, even as an unofficial ally against Russia. The European and transatlantic allies are resolved to not provide such guarantees. Unfortunately, at this stage NATO might not be able or willing to defend Ukraine against a Russian invasion, and Ukraine cannot defend itself. If there is any scope for an agreement between Biden and Putin, it should aim to avoid a return to Europe’s Cold war missile crisis. Despite the degree of mistrust between NATO and Moscow since Russia’s 2014 annexation of Crimea, re-starting high level strategic stability talks, rebuilding arms control agreements and addressing Russia’s security concerns over Ukraine cooperation with NATO might be the only way to preserve Ukraine’s territorial integrity. Military buildup and nuclear posturing on both sides will not bring de-escalation, but may bring Europe to the brink of war.

Keywords: Ukraine, Russia, NATO, EU, Putin, borders, Biden, Belarus, security

E-ISSN: 2014-0843


  • Agnieszka Nimark

    Agnieszka NIMARK

    Investigadora Sénior Asociada