Perhaps you might like some of these:

The Breaking Point: Sedan and the Fall of France 1940, Robert Doughty

Stalking the Vietcong: Inside Operation Phoenix: A Personal Account, by Stuart A. Herrington, originally published as Silence was a Weapon (1982).

On the Road to Stalingrad: Memoirs of a Woman Machine Gunner,Zoya Smirnova-Medvedeva

No Margin For Error: The Making of the Israeli Air Force, by Ehud Yonay (1993)

The Operators: On the Streets with Britain's Most Secret Service, by James Rennie, on 14 Company's undercover work in Northern Ireland in the 80's.

One Up: A Woman In Action With The SAS, by Sarah Ford, autobiography
of a woman who served with 14 Intelligence Company in Northern Ireland.

Wasp, Eric Frank Russell (SF, 1971) in which one man is dropped on an alien planet to keep them busy until they swat him.

Sleeping Planet, William R. Burkett (SF, 1965) in which aliens put everyone on earth to sleep except for a handful who conduct psywar ops against them. Fun but can be hard to find.

I won't list Daniel Suarez' recent Daemon and Freedom because they hardly count as obscure.