ABANDONED. Spy style thriller about an ex-Army guy who plans revenge on somebody who commited war crimes

[Mr]

Recently published (late 2019 / early 2020) by a well known male author.

An Army recruit sees some horrendous war crimes in Eastern Europe. After leaving the Army he moves to Scotland.

Some years later, the perpetrator of the war crimes turns up in London and the ex-Army guy stalks him, with a view to getting his revenge.

[Kris]

Mr Matthew, please post a new comment if you're still looking for this book - or if you found it.

Mr Matthew (OP) was last active on the site in February 2020. Moving to Abandoned folder.