President Obama has warned of potentially disastrous consequences for the global economy if European leaders failed to contain the debt crisis in Greece. He said defaulting Greece could lead to an uncontrolled spiral triggering events worldwide. He urged the visiting German Chancellor Angela Merkel to work with other European leaders to ensure stability.President Barack Obama and visiting German Chancellor Angela Merkel both say they believe it is inevitable that Libyan leader Moammar Gadhafi will step down. The two leaders also discussed the uprisings in the Middle East and the state of the world economy. Both the leaders discussed numerous issues during the German leader’s White House visit, including the sometimes contentious topic of Libya.