sentences:  In the first decade of the 21st century, the United States Army began another reorganization, giving the division four brigades and placing more emphasis on the brigade as the main tactical element, with the division acting more like a corps headquarters, parceling out support units to the brigades.Most European armies reorganized their divisions as triangular divisions during World War I, and retained that structure since.Many European armies now place greater emphasis on the brigade and in some cases, such as the Portuguese and the Belgian armies, have eliminated the division entirely as a tactical unit.