Each level of war is essential to achieve success, and are all equally important. The Ludendorff Offensives of 1918 provide an illustration of why the operational level is essential.
President Putin made three foundational assumptions in launching his war against Ukraine that should have been correct but were not. First, Putin assumed the invasion of Ukraine would be a quick and easy fight. Second, he assumed the world would denounce the invasion but tacitly allow it. Third, Putin assumed the war would deter NATO expansion.