If you're hoping for a war refugee story in the vein of The Pianist, this is probably not exactly what you want. If, however, you're interested in an introspective, moody, and melancholy story of a man trapped both metaphorically and literally, then this is the novel for you.
Our protagonist is a sad little man, looking for something to give his life colour and meaning, not realizing that a search like that shouldn't go outwards. And the whole "World War" business is hindering him quite a bit, obviously. As he writes letters to the wife he left behind in the occupied Czech Republic, he tells her how he foolishly ran away to be with the woman he thought he loved, how he lost his chance to come back home, and how his paralyzing insecurities and doubts have lead him to the place where he is now: a damp, dark cellar with no hope of ever getting his life back on track.
This is less of a war novel than one might expect, even if you take into account the fact that this is an epistolary character study and not another skirmish-based gung-ho action book.
The protagonist is intentionally unlikeable, a worm of a man, who has everything and throws it away on a whim and, to put it mildly, digs his own grave. Is it weird to feel no sympathy towards a man in a life-or-death situation in the midst of a bloody, horrible war? Hopefully not, because that's how you're likely to feel about our nominal hero.
What elevates the book above its milquetoast bore of a protagonist is the writing. Its this expressive yet reserved style that absolutely flourishes specifically due to the nature of the narrator. It is easy to believe that these bursts of flavourful, manic descriptions of people, feelings, and conditions, really are just the ramblings of a man going insane. And make no mistake, our "hero" is not dejected or mildly dispirited by his (if I'm being honest) mild predicament. He is going off the deep end, talking about having nightmares while awake, crawling on walls, and it all feels rather like a strangely poetic fever dream.
All in all, what this lacked was a protagonist who could elicit stronger feelings. I couldn't hate him, so I wasn't rooting against him and I couldn't like him, so I definitely wasn't hoping for him to make it out okay. But this is worth reading for the prose alone, if only to see a glimpse of how good writing can elevate a weak story/character.