MOSCOW - Vladimir Putin appealed for unity in Russia after being sworn as president on Monday and pledged to strengthen democracy in his new six-year term."I will do all I can to justify the faith of millions of our citizens. I consider it to be the meaning of my whole life and my obligation to serve my fatherland and our people," Putin said in a brief speech at his inauguration in the Kremlin."We will achieve our goals if we are a single, united people - if we hold our fatherland dear, strengthen Russian democracy, constitutional rights and freedoms."Putin, who was president of the former Soviet republic from 2000-2008 and is returning to Russia's highest office after four years as prime minister, said he and the Russian people had already trodden a "difficult path" together."We believed in ourselves and in our powers, strengthened the country and restored the dignity of our great nation. The world has seen Russia reborn, and this is the result of the efforts of our people - shared, intensive work in which everyone has made a personal contribution."He praised Dmitry Medvedev, the ally he steered into the Kremlin when he faced a bar on a third straight term in 2008 and who is set to become prime minister in a job swap that has angered many Russians who are tired of the same leaders."Today we have everything we need to move forward and create a dynamic and developing state: A stable economic and social basis, an active and responsible civil society," Putin said. "I see in this a great service on the part of Dmitry Anatolyevich Medvedev."