Why do some accuse James Buchanan of near treason?

Some accuse James Buchanan of near treason due to his inaction and perceived complicity during the secession crisis leading up to the Civil War. Critics argue that he failed to confront the Southern states' secession and protect the Union, effectively enabling their departure. His administration's policies and decisions are seen as betraying the constitutional duty to preserve the nation, contributing to the war's outbreak. This lack of decisive leadership during a critical moment in American history has led to accusations that he prioritized political expediency over national unity.