Carolyn Kaster/AP/Press Association Images. All rights reserved.The previous column in this series contrasted Donald Trump's isolationist geopolitical stance with plans to increase the size of all four branches of the US armed forces – army, navy, airforce and marine corps, with the last constituting the Pentagon’s major instrument of expeditionary warfare.

The column concluded a little cautiously, suggesting that if such an expansion went ahead it did not necessarily imply Trump's keenness to go to war. But the situation might change if domestic reversals made an "overseas adventure" look a tempting diversion:

“In all of this there may be an element of giving Trump increased options in a time of crisis, but the fact remains that this will be a substantial expansion at a time when the Republicans control both Houses of Congress. Perhaps the most important thing to remember is that if Trump’s first term runs into trouble, not least with an inability to deliver on domestic campaign promises, then that would be the kind of circumstance where an overseas adventure – “war” in other words – might become rather attractive.  What these various expansions mean is that in such circumstances the military will be in a stronger position to oblige” (see "Trump and the Pentagon", 7 November 2016).

The case against this conclusion might be that it takes too long-term a view. For a start, it's doubtful that Barack Obama's two terms will end with significant successes in areas where the United States military is now directly involved: Iraq, Afghanistan, and lesser areas of Islamic State activity such as Libya (see "Trump in context", 11 November 2016).

By this stage, it had long been expected that Mosul would have been purged of IS forces and that even the capital of the caliphate, Raqqa in northern Syria, would have been under heavy pressure; that there would have been sufficient progress in Afghanistan to resume the gradual drawdown of US forces; and that the coastal city of Sirte would have been freed from IS control.

Add the grim siege of Aleppo and relations with the Kremlin, and the challenges mount. Thus, Trump may well inherit acute problems that will demand his attention from day one of his presidency, 20 January 2017.

The limits of power

A brief glance at the condition of these three main conflicts where American forces are pitted against IS shows how wide in each case is the gap between hope and reality. 

In Libya, forces of the nominal government launched operations in May 2016 against several hundred IS paramilitaries occupying the coastal city of Sirte. Initially, there was confidence that victory would come within weeks. Some analysts questioned this scenario, saying that IS fighters might simply melt away and re-emerge elsewhere in Libya in the event of a notional defeat. Yet the loss of Sirte would still be a blow to the group.

In the event, Sirte did not fall. Instead, the operation turned out to be so difficult that US ships off Libya's coast deployed naval air-power to conduct bombing raids in early August. Scores of air-strikes were launched in the ensuing weeks: October saw the peak with 187, and there were 368 over fifteen weeks.

Even this has not proved enough. IS still occupies a core part of the town. It may well be displaced before Trump's inauguration, but its survival under an intense six-month siege suggests that even then it will be far from finished in Libya as a whole (see Alison Pargeter, "Failing Libya", 18 October 2016).

In Afghanistan, endemic insecurity shows every sign of intensifying. Ashraf Ghani's government in Kabul may be somewhat more technocratic and effective than Hamid Karzai's, but corruption remains hard to curb and maladministration a serious problem. The Taliban and other armed opposition groups maintain their ability to stage deadly attacks, such as the bombing of a Shi’a mosque in Kabul on 21 November, which killed at least thirty-two people 

What is happening outside Kabul is even more worrying for the government. The Taliban has maintained control of key rural areas, notably a very large part of Helmand. The province is at the centre of illicit opium production and a good source of revenue for the movement. Its persistence has stymied Obama's plan to withdraw all US combat-troops by the end of 2015, leaving overall US force levels at over 9,000. This legacy is yet another problem for the incoming president.

In Iraq, the assault on Mosul has run steadily into the ground as it moves into its sixth week. For the first two weeks, Baghdad's government was confidently claiming progress through the outlying villages to the east of the city, then into some of the city's outer urban districts. A slowdown followed, as the attackers' limitations were exposed. The Iraqis' elite forces were insufficient to take the whole city, while the regular army units couldn't overcome determined paramilitaries who were well prepared, well armed, and highly skilled in defensive urban warfare. In addition, they had the use of a formidable network of tunnels constructed during IS's rule over the city 

Thus, Iraqi government forces have been unable to force an advantage. Now, in the last week of November, there is a near stalemate. That could still change: there is a slight possibility of a military breakthrough, with IS deciding to begin withdrawing the bulk of its forces in order to fight another day. Yet the space for this outcome is narrowing. Meanwhile, IS's ability to strike elsewhere in Iraq is shown by the bombing on 24 November at Hilla, southeast of Baghdad, which killed at least seventy Shi'a pilgrims from Iran. It's quite possible that Trump could face big decisions around the end of January, where the world will be looking on to see if he really will effect a fundamental change of policy and reduce the American commitment.

All in all, the indications now are that Trump will be mired in foreign-policy and security crises at the very time he had been hoping to prioritise domestic changes via presidential decree. The plan was to ensure that the incoming president would use the first hundred days to showcase what he intended to do, on a much larger scale, over the following four years. Events, though, are already conspiring against him. Even as a populist president of the world’s strongest military state, Trump may be about to learn the limitations of power.