On what constitutional basis did the supreme court deny korematsu's appeal answers

The court claimed "military urgency." This allowed them to violate amendment rights. The design of the order was to keep another "Pearl Harbor" from happening. However, 2 judges dissented claiming that the order was nothing more than legalized racism. Also, it should be noted that only Japanese Americans were rounded up. No one of German descent was ever rounded up or persecuted for possibly being a spy solely based on their country of origin. We also had lots of Nazi spies in the country that were allowed to operate due to their being "white" and being able to "blend in".