Wasp.

I think some reviewers take this book too seriously. Eric Frank Russell wrote humorous sf stories in which clever humans ran rings around stupid but very human-like aliens (or, sometimes, around stupid humans). His stories are quite entertaining if you like that kind of thing, although they're rather dated by now: the author lived from 1905 to 1978 and never knew the Internet, mobile phones, or laptop computers. Most of his writing was done when computers were non-existent, or very few and very primitive.

This story is a bit more carefully thought out than most of his others, but it's essentially the same kind of thing.

You can read the activities of Russell's hero (James Mowry) as an anticipation of the kind of terrorism that often makes the news these days, although I think that would be an inaccurate misunderstanding. Mowry is acting as the agent of a large and respectable government, and his function is to soften up the enemy in advance of a conventional military attack. It's not really at all like 21st-century terrorism, although it's true that Mowry and 21st-century terrorists are both cost-effective ways of upsetting an enemy.

In a sense, it may be a disadvantage that Russell took this book a bit more seriously than usual: it's not as funny or light-hearted as most of his other work. However, I suppose it's quite interesting: it emphasizes the point that a country can be seriously disrupted at low cost by a small number of secret agents; which is probably still true, although the methods may have changed.