Colin S. Gray on Thucydides and the Definition of Future Threats

Thucydides leaves us no doubt that the principal threat to the security of Athenians flowed more from the distinctly flawed working of the empire’s democratic politics, especially its procliv­ity to promote crowd pleasing demagogues who were short of competence, high ethical standards, or both, than from vengeful Persians or strategically pedestrian Spartans. Political ruin tends to begin and end at home. Students of international relations need to remember this plain warning from the historical record.