Barack Obama, the next president

I felt happy when i heard that Obama will be the next president. You know it's like a miracle happen because in U.S history never have any African American person become president but now things have change http://www.ajc.com/metro/content/metro/stories/2008/11/05/106_year_old_obama_speech.html, but there are two things that i'm worried.The first thing is: There're many American's mayors calling out for help from Obama beacause of a national economic crisis that has slammed budgets in many big cities, suburb and small town http://www.msnbc.msn.com/id/27583162/. The second thing is that if it's alright to withdraw U.S troops from Iraq, i know U.S.A lost a lot of money and many soldiers have died about this war but if U.S. withdraw will Iraq get revenge ? My opinion is the U.S. troops should stay in Iraq because if U.S.troops withdraw , the Iraq can get revenge anytime they want http://www.usatoday.com/news/military/2008-11-11-obama-wars_N.htm.