The numbers are small, the terrain unfamiliar, the cast of characters chaotic and the clash of interest hard to decipher.
Nevertheless, President Donald Trump's sudden, perhaps impulsive decision to withdraw 2,000 American military personnel from northeastern Syria, as well as the resignation of Defense Secretary James Mattis in response, has raised a question of continuing pertinence in American policymaking.
That question is not about civilian control of the military. Retired Gen. Mattis was as scrupulously respectful of the commander-in-chief's authority as he was when then-President Barack Obama removed him abruptly from head of Central Command in January 2013, apparently without even a phone call.
In his resignation letter this month, Mattis endorsed "treating allies with respect and also being clear-eyed about both malign actors and strategic competitors." Key sentence: "We must do everything possible to advance an international order that is most conducive to our security, prosperity and values."
In Mattis' view, "everything possible" includes retaining 2,000 troops in northeastern Syria for some time, perhaps indefinitely. Trump as presidential candidate took -- and as commander-in-chief takes -- a different view.
It's a view encapsulated in the over-simple phrase "we're not the policeman of the world" and in the more sophisticated argument that American interests in many corners of the world are not worthy of any sacrifice of American blood or dollars, particularly when no clear victory is in sight. American forces have been in Afghanistan for 17 years, starting just days after the 9/11 attacks launched by Afghanistan-based Osama bin Laden. As many Trump fans and others point out, American goals in Afghanistan have not been achieved and seem likely to never be fully achieved.
The case for military deployments in Afghanistan and Syria cannot be as attractively and succinctly stated. It is presented by some in terms of cost-benefit analysis. Syria has been, in the words of Washington Post veteran foreign affairs correspondent David Ignatius, a "low-cost, high-impact mission."
But it can be appreciated more vividly by those with some knowledge of history. Andrew Roberts' recent splendid biography of Winston Churchill, for example, recalls the time when British military forces were stationed, indefinitely or for many years, at the margins between lands where the rule of law tended to prevail -- not all of them British colonies -- and lands where it didn't.
The young Churchill in the 1890s fought in cavalry charges in present-day Pakistan and Sudan. As colonial secretary in 1921-22, Churchill created Iraq and dispatched 40,000 troops there to "establish order." They weren't withdrawn until 1928.
There was a significant cost to this policing of much of the world: deaths, injuries and the contempt memorialized in Rudyard Kipling's "Tommy" poem: "For it's Tommy this, an' Tommy that, an' 'Chuck him out, the brute!'/ But it's 'Saviour of 'is country' when the guns begin to shoot."
This was a burden, nevertheless, that Britain was willing to bear until 1968, when Labour Prime Minister Harold Wilson announced he was ending British military operations "east of Suez." It is no coincidence that in the decade that followed, the Middle East saw major wars and a vast increase in oil prices.
The argument for extended or permanent military patrols at the edges of the civilized world is that dangers to the United States and its allies lurk there -- dangers whose character and dimension are unknown and unknowable until the damage is done.
This is not and cannot be fail-safe work. Mistakes will be made in making local alliances and identifying local enemies, in short-term calculations and long-term strategy. In 1842, the British lost all but one solider in a 4,500-man retreat from Afghanistan. In 1885, the British army seeking to rescue Gen. Charles Gordon from the Mahdi arrived in Khartoum days too late.
The Victorian public followed these conflicts but did not regard them as major wars, like those waged earlier against Louis XIV or Napoleon, or the future world wars of 1914-18 and 1939-45. In this perspective, the penchant of American politicians and journalists to treat conflicts like those in Afghanistan and Iraq as world wars seems misguided.
They were never likely to provide clear end points like Hitler's suicide in the bunker or Japan's surrender on the USS Missouri; or optimal results like the establishment of democratic rule-of-law governments there. Critics of these deployments have got this right.
But that doesn't mean they are always useless or not worth the cost. In a world where the costs of dangers averted and disasters avoided are unknowable, it's wise to bet that such deployments are needed to foster, in Mattis' words, "an international order ... conducive to our security, prosperity and values."