Burke, in his Speech on Conciliation with America, advising against the British use of force against the colonies:
“First, Sir, permit me to observe, that the use of force alone is but temporary. It may subdue for a moment; but it does not remove the necessity of subduing again: and a nation is not governed, which is perpetually to be conquered.
"My next objection is its uncertainty. Terror is not always the effect of force; and an armament is not a victory. If you do not succeed, you are without resource; for, conciliation failing, force remains; but, force failing, no further hope of reconciliation is left. Power and authority are sometimes bought by kindness; but they can never be begged as alms by an impoverished and defeated violence.
"A further objection to force is, that you impair the object by your very endeavors to preserve it. The thing you fought for is not the thing which you recover; but depreciated, sunk, wasted, and consumed in the contest. Nothing less will content me, than whole America. I do not choose to consume its strength along with our own; because in all parts it is the British strength that I consume. I do not choose to be caught by a foreign enemy at the end of this exhausting conflict; and still less in the midst of it. I may escape; but I can make no insurance against such an event. Let me add, that I do not choose wholly to break the American spirit; because it is the spirit that has made the country.
"Lastly, we have no sort of experience in favour of force as an instrument in the rule of our colonies. Their growth and their unity has been owing to methods altogether different. Our ancient indulgence has been said to be pursued to a fault. It may be so. But we know if feeling is evidence, that our fault was more tolerable than our attempt to mend it; and our sin far more salutary than our penitence."
This, it seems to me, is a very good example of the conservative case for non-intervention. Burke's concern (to Richard Weaver's chagrin) is not whether or not the British should subdue the colonies, but whether or not it can. This is what Russell Kirk called "the art of the possible."
Of course, the question of ought is still valid, but I think it's interesting that, for Burke, the question of possibilities comes first, at least in his argumentation.