Written by one of Russias earliest communist thinkers, Kropotkin expresses a worldview similar to Marx. Anarchism is a crisis philosophy, that gets adopted during stressful times to meet what feel like the practical demands of life. In this philosophers' eyes, all the world's societies area conflict between the local tight-knit community that settles its own disputes and an outside autocratic force that seeks to establish its authority over people.
Kropotkin was a man of his time and place, the time being pre-WWI, and the place being Czarist Russia, where the corrupt imperial officials where known for terrorizing the local peasant populace. (European anarchists, the eastern-European ones especially, and their general blue-collar focus has always come off a bit jarring. Where in Europe, those who become anarchists are usually doing so in the name of labor. In contrast anarchist communes in the US are often composed of artists and political activists, they tend to more approachable. Maybe that's just my two-bits).
Back to the matter at hand, this is a philosophical tract justifying anarchism by claiming it is applying scientific justification to it. Additionally, Kropotkin attacks the ideology of the day: that people need a strong state to keep them from turning into murderous monsters ('peace through power', you can see it touted by political figures every-time elections roll around). If you didn't know about the time and place, one might even call certain parts of it borderline libertarian.
Is it interesting? Yes, for me at least.
Useful, and true? Noooooooo.