Which war in 2001 is subjectively deemed a world war?
War on Terror The War on Terror (WoT), also known as the Global War on Terrorism (GWOT), is a metaphor of war referring to the international military campaign that was launched by the U.S. government after the September 11 attacks in the U.S. in 2001.  U.S. president George W. Bush first used the term ""war on terrorism"" on 16 September 2001, and then ""war on terror"" a few days later in a formal speech to Congress. In the latter speech, George Bush stated, "Our enemy is a radical network of terrorists and every government that supports them." The term was originally used with a particular focus on countries associated with al-Qaeda. The term was immediately criticised by such people as Richard B. Myers, chairman of the Joint Chiefs of Staff, and more nuanced ones subsequently came to be used by the Bush administration to publicly define the international campaign led by the U.S.; it was never used as a formal designation of U.S. operations in internal government documentation.
Two-front war In military terminology, a two-front war is a war in which fighting takes place on two geographically separate fronts. It is usually executed by two or more separate forces simultaneously or nearly simultaneously, in the hope that their opponent will be forced to split their fighting force to deal with both threats, therefore reducing their odds of success. Where one of the contending forces is surrounded, the fronts are called interior lines.