NEW YORK -- Defending Bashar Assad as the only "legitimate" leader of the Syrian state, Russian President Vladimir Putin recommitted Moscow's support to his government on Monday in a speech to the United Nations.In his first address to the assembly hall in a decade, Putin chided western powers for their efforts to undermine Assad, who has presided over a country now four and a half years enmeshed in violent civil war. According to the UN, over 210,000 Syrians have died since 2011, and half of the country's population has been displaced."We should finally acknowledge that no one but President Assad's Armed Forces and Kurd militia are truly fighting the Islamic State," Putin said. Warning that foreign fighters recruited from Islamic State may one day return home to Europe and Russia, he added: "We cannot allow these criminals who tasted blood to return home.""The situation is more than dangerous," Putin said. "In these circumstances, it is hypocritical and irresponsible to make loud declarations about the threat of international terrorism while turning a blind eye to the channels of financing and supporting terrorists."Putin is attempting to lead an anti-Islamic State coalition built around Assad, beginning with an effort to walk countries back from their calls for his departure. In the last month, Russia has begun a significant forward deployment of Russian military equipment on newly-built Russian military bases in Western Syria. In his speech, Putin suggested a United Nations Security Council resolution that would authorize the fight against Islamic State— and condemn all efforts to suppress it.US President Barack Obama rejected Russia's strategy on Monday, warning that any military escalation would further destabilize the region. He also reiterated his assertion that Assad had lost "legitimacy" as ruler of Syria.Nevertheless, Obama also called for a realist "compromise" with Russia and Iran that will definitively end the fighting. Putin took aim at the United States with several veiled references to the policies of the Bush administration. He condemned efforts by the former Soviet Union to export its ideological governing model abroad, and chided the United States for its own efforts to spread democracy around the world."We should all remember what our past has taught us," Putin said. "We also remember certain episodes from the history of the Soviet Union. 'Social experiments' for export, attempts to push for changes within other countries based on ideological preferences, often led to tragic consequences and to degradation rather than progress.""It seems, however, that far from learning from others' mistakes, everyone just keeps repeating them," he continued. "And so the export of revolutions, this time of so-called 'democratic' ones, continues."But Obama continued that effort in his own speech earlier that morning."It's not simply a matter of principle; it's not an abstraction," Obama said. "Democracy— inclusive democracy— makes countries stronger."