From Zachary Keck:
…As the wise philosopher Rob Farley once cautioned in these pages, “accidental wars rarely happen,” and instead are usually the result of deliberate state policy. And in this regard, WWI is no exception, at least according to Dale C. Copeland.
In his instant classic, Origins of Major Wars, Copeland developed a theory he called “dynamic differentials theory” to explain the causes of great power conflicts. To slightly oversimplify, dynamic differentials theory argues that declining states initiate wars when they are still clearly militarily superior but they believe they are in deep and irreversible decline relative to the rising state.
In such a situation, the leaders of the declining state come to see war as the only way to prevent the rising state from overtaking it as the most powerful nation in the system, thereby becoming a major security threat. Dynamic differentials theory posits that these leaders are most likely to initiate war when they believe they have maximized their relative power– that is, when they believe their relative military power is peaking and delaying war will only allow the rising nation to grow relatively stronger….
Read more at The Great Myth: World War I Was No Accident | The Diplomat.