Josef Silverstein, a scholar and outspoken critic of Myanmar’s repressive military leaders over a turbulent half-century, died at his home in Guilford, Conn. He was 99, The New York Times reported.

Professor Silverstein, who taught international relations and Southeast Asian studies at Rutgers University in New Jersey, focused on democracy and human rights in Myanmar both as an academic expert and as an on-the-ground adviser to opposition groups.

Because of his criticism of the military leadership, he was denied entry to Myanmar for most of his career. As a result, he frequently met with rebel leaders along the borders with Thailand and China, advising them on the concepts of federalism and constitutional law.