What were the most important reasons that the spring 1918 offensives did not achieve decisive victory for Germany? At the strategic and operational levels, how are the reasons that you have identified important for military planning today?

Based on the required reading of Warfare, Cambridge Illustrated History by Geoffery Parker, pp 298-294, the most important reasons that the Spring 1918 offensives did not achieve a decisive victory for Germany are:
Lack of any decisive strategic goal
Failure to exploit tactical success while “reinforcing failure”
Forming elite units within The German Army, by taking the best soldiers from existing units.
Lack of any attempt at a political solution
Germany felt it had to win at any cost, while the Allies, with American soldiers entering the conflict in larger numbers, could settle for limited losses and simply delay Germany
These reasons are important in military planning today, because now, as then, our knowledge and ways of waging warfare change with new technology, ideas and concepts; however the military objective, to destroy an enemies will and ability to fight must be understood by the politician while the political objective, to successfully defeat an enemy and restore peace and economic trade, must be understood by the military in order to achieve a workable strategic goal.   In simple terms, we want to win the war, not just battles.   The battles and military operations must create an environment to restore peace and economic trade.
If we look at   Erich Von Ludendorff, Germany’s Commanding General, his concepts of “Defense in Depth” and “Attack in Depth” were revolutionary in their times and many of the concepts are practiced today, however the question is, what did he hope to achieve with these operational tactics.   History shows us his opening offensive was successful, though the allies had realized the benefit of “Defense in Depth” they had not yet developed their operations and had not employed this concept...