MADRID – Just three days before his return to the Kremlin as Russia’s president, Vladimir Putin met behind closed doors at his residence in Novo-Ogaryovo, outside Moscow, with US National Security Adviser Tom Donilon, who was there to transmit President Barack Obama’s renewed determination to strengthen cooperation with Russia.

But Donilon returned home empty-handed: Putin will attend neither the G-8 summit on May 18-19 at Camp David, nor the NATO summit in Chicago on May 20-21, despite Obama’s effort to accommodate Russia by moving the G-8 summit from Chicago.As a result, what would have been the first meeting between Obama and Putin after his return to the Russian presidency has been postponed until the G-20 summit in Los Cabos, Mexico, set for June 18-19. This delay has provoked much speculation.Some point as a cause of Putin’s absence to recent tensions between Russia and the United States arising from Putin’s increasingly harsh response to the protests by his opponents at home. Others suggest that Putin’s aloofness stems from Kremlin infighting.Whatever may be driving Putin’s behavior, this month’s two summits will affect relations between the two countries considerably, given the global security issues to be discussed by the G-8 and the need to arrange for Russia’s participation in NATO’s anti-missile shield.Two matters – besides the shaky global economy – are especially important for the G-8 summit. First, Iran’s nuclear program is now on the diplomatic front burner. After more than a year of deadlock, negotiations resumed in April. Russia, as a permanent member of the United Nations Security Council, participates in these talks, and its cooperation is essential to resolving one of today’s most vexing international problems.Much the same can be said of Russia’s role in resolving the crisis in Syria, owing to the strategic relationship that the two countries have maintained since the Cold War. Indeed, with the growing possibility that former UN Secretary-General Kofi Annan’s peace plan for Syria might fail, and that civil war might erupt, Russia could be the international community’s only effective interlocutor left.In addition, it is essential to align the positions of Russia and the West on the anti-missile shield system now being developed by NATO, which will be a subject for discussion in Chicago. The principal aim of the system is to protect Europe and the US from possible attacks by short- and medium-range ballistic missiles from Iran and North Korea. But Russian leaders are skeptical about the true objectives of a shield, believing that it would undermine Russia’s security by curtailing the retaliatory (and thus deterrent) capacity of its nuclear missiles.In 2009, the "approach by stages of adaptation” launched by Obama seemed to ease bilateral tensions and prepared the way for the 2010 New START arms-reduction treaty, in which Russia and the US took a strategic leap to cut the number of nuclear-missile launchers by half. Following on this progress, at the end of 2010, the Russians agreed to study the possibility of cooperating with NATO on anti-missile defense.But the US was unable to offer legal – not just political – guarantees that an anti-missile system based in Europe would not obstruct Russia’s strategic potential. As a result, Russia is now so mistrustful that its military chief of staff, General Nikolai Makarov, recently declared that his country would not rule out pre-emptive attacks to destroy any part of the anti-missile shield that it views as a threat to its own security.One of the main arguments for this posture was Russia’s uncertainty about whether later steps in the "approach by stages of adaptation” might be a threat to its strategic ballistic missiles. Moreover, Russia opposes the deployment of military facilities in countries – like Romania – that joined NATO after 1999, a point made recently by former US ambassador to Ukraine Steven Pifer of the Brookings Institution.In view of the seriousness of the questions under consideration at the two summits, Putin’s presence would have been helpful. In addition to the inherent value of improving the personal chemistry between leaders, reducing tensions in the relationship between Russia and the West has become indispensable, given that negotiations over the missile shield, Iran, Syria, and other issues are bound to be long – and that the solutions are linked.Indeed, acceptable solutions today would open the way for an unprecedented nuclear-arms agreement in 2013. This is a matter of major importance, for which a good understanding between Russia and the US is essential.We must do everything within our power to realize Donilon’s proposal to Putin to, in essence, "reset the reset” and bridge the gap between the two countries concerning the future disposition of their nuclear arsenals. For Obama, success would vindicate the Nobel Peace Prize that he was awarded in 2009. Russia, we can be sure, would benefit as well.Javier Solana was Foreign Minister of Spain (1992-95), Secretary-General of NATO (1995-99), and EU High Representative for Foreign and Security Policy (1999-2009). He is currently President of the ESADE Center for Global Economy and Geopolitics and Distinguished Senior Fellow at the Brookings Institution.Copyright: Project Syndicate