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.