Jomini's objectives

Speaking of Jomini, here is a passage from the US 1862 edition of his Art of War. I cite this in the hope we can be rid of the procrustean nostrum Make the enemy your objective:
There are two classes of objective points,—objective points of maneuver, and geographical objective points. A geographical objective point may be an important fortress, the line of a river, a front of operations which affords good lines of defense or good points of support for ulterior enterprises. Objective points of maneuver, in contradistinction to geographical objectives, derive their importance from, and their positions depend upon, the situation of the hostile masses.

In strategy, the object of the campaign determines the objective point. If this aim be offensive, the point will be the possession of the hostile capital, or that of a province whose loss would compel the enemy to make peace. In a war of invasion the capital is, ordinarily, the objective point.
More, with reference to risk:
As to the choice of objective points, every thing will generally depend upon the aim of the war and the character which political or other circumstances may give it, and, finally, upon the military facilities of the two parties.

In cases where there are powerful reasons for avoiding all risk, it may be prudent to aim only at the acquisition of partial advantages,—such as the capture of a few towns or the possession of adjacent territory. In other cases, where a party has the means of achieving a great success by incurring great dangers, he may attempt the destruction of the hostile army, as did Napoleon.
Did the Union ever have the political capacity to incur "great dangers"? Demanding great results without incurring great danger is exactly what we would expect of politicians.
There is another class of decisive points to be mentioned, which are determined more from political than from strategic considerations: they play a great part in most coalitions, and influence the operations and plans of cabinets. They may be called political objective points. [...] This subject is so extensive and so complicated that it would be absurd to attempt to reduce it to a few rules. The only one which can be given has just been alluded to, and is, that either the political objective points should be selected according to the principles of strategy, or their consideration should be postponed till after the decisive events of the campaign.
Emphasis added. Have a look.