Desert Hell is about the British getting mixed up in what was then known as Mesopotamia, now known as Iraq, during World War I. Whereas Tigris Gunboats was concerned almost solely with the efforts of the naval arm, Desert Hell is focused more on the army, and beyond that, the political aspect.
The political side does mirror the military side strangely well. For the Army, every city or area they took did not solidify their position, but instead required them to advance further into the desert. To take more positions to protect the ones they'd already taken. And given that the British largely left supplying the forces to the Indian Government for the first couple of years, and the Indian Government was trying to run everything on an extremely tight budget, which led to them being rather skinflints. Which meant the forces were constantly running short of supplies, in large part because no one would approve the expenditure for a railway to easily ship supplies and reinforcements to the front.
On the political side, the longer the British were involved, the more complicated things got for them. There was a lot of noise about self-determination, and the British had agreed, which meant no making it a direct colony. But The Powers That Be were not entirely convinced the Arabs of the region could govern themselves as a unified nation (although they gave it much more consideration that I would have expected). And the Indian Government apparently had visions of Iraq being incorporated under their control. And Arnold Wilson, who was sort of running things in Mesopotamia during the latter stages of the war and after, completely ignored all the directives that he was not to set up a government run by the British, and did that anyway. The British and French were bickering over where to draw boundary lines for what became Iraq and Syria. The British seemed to recognize the Kurds as a distinct group, who should probably therefore be granted the opportunity to form their own nation, but a) they didn't see any sort of unifying nationalist movement, and b) it was about that time people started to realize the value of the oil in the southern range of the Kurds' home, and the British wanted to keep that in Iraq, where they'd have access, and well, there you go.
One thing the book brought up that was an apparent point of conversation among the British at the time, with self-determination, who are the selves doing the determining? Obviously when speaking of Mesopotamia, the answer should at least start with, "Not the British (or the Americans, for that matter)". Even if the majority of the people living in that part of Mesopotamia were Arabic, they aren't one homogeneous mass. There are religious differences, old grudges between different tribes, and the usual jockeying for power. How do you set up a system for people to devise a system of government for themselves that works for all groups? I'd think you let those people try to draw up their own borders, rather than imposing them, but then there's the question of what happens if more than one party wants a specific location. In Iraq, as in other places before and since, it didn't go so well. The Sunnis dominated the political and military sphere, and it went badly for the Shias, the Assyrians, the Jews in Baghdad, and the Kurds. Townshend points out the British either failed to make protection of minority rights a strict condition of Iraq becoming totally independent, or didn't really enforce it.
Once again, history is really depressing. It wasn't terribly surprising that the time everyone seemed to be closest to working together was when everyone decided they wanted the British out in 1920, and there were a series of small rebellions across the country. It didn't really work, the British utilized the advantage of air power and more troops, but for a little while, people were on the same page.
'From being a majority in Kurdistan, the Kurds became a minority in Iraq. The international community had spoken, and its logic was instructive. The argument that Kurdish opinion was so divided that there was, in effect, no Kurdish opinion, implied that only those peoples with a fully developed national political organization in 1919 could qualify for self-determination. And the argument was wrong on one key issue at least: subordination to an Arab government was universally rejected by Kurds. This had been reported so often by British officials that it is hard to see Britain's eventual stance as anything other than willful self-deception. Kurdish identity was inconvenient.'