Why didn't Buchanan do anything when the south seceded?

President James Buchanan believed that the Constitution did not grant him the authority to prevent states from seceding. He viewed secession as illegal but also thought that using force to stop it would be unconstitutional and could provoke civil war. His administration was paralyzed by indecision and a lack of support from Congress, leading him to adopt a passive approach during this critical time. Ultimately, Buchanan's inaction is often criticized as a failure to address the growing crisis that ultimately led to the Civil War.