Short answers, pulled from the story.
A strategic military goal defines the desired end-state of a war or campaign. It is the highest level of organisational achievement in a military organisation and is usually set by national defence policy. Goals can be framed in terms of military posture, territorial gains, diplomatic conditions, economic outcomes, or evidence that an enemy's will to fight has broken.
A strategic goal states the overall desired end-state, while strategic objectives are the specific, often physical, milestones that mark incremental progress toward that goal. Objectives are necessary because high-level strategic goals are often abstract and difficult to assess without concrete, measurable benchmarks.
Military history shows two recurring problems: goals change mid-campaign due to shifts in a state's economic, political, or social conditions, and the criteria used to measure achievement drift even when the stated goal remains the same. Both factors appeared together during the Vietnam War.
The American strategic goal was to preserve a fragile South Vietnamese regime against lightly armed opponents, not to destroy an organised conventional military force for which the United States had prepared. War costs escalated beyond predictions, political leadership changed and reduced commitment, and American society underwent radical transformation, all of which altered how the goal was defined and assessed.
Strategic goals correspond to operations performed by a front or a fleet on a theatre scale, and by an army group. During the Second World War, the Soviet Red Army used formations called Red Army Fronts to operate at this level.
Yes. Strategic goals can be set in terms of diplomatic or economic conditions, not only military victory or territorial gain. A goal may also be defined as limiting the scope of a conflict rather than winning it outright.