MILWAUKEE, Wis. (WTAQ) - A Milwaukee native who headed a think tank that seeks greater cooperation between North America and Europe has died.

Former US diplomat Ron Asmus died from cancer over the weekend. He was 53.

Six years ago, Asmus became the executive director of the Brussels office of the German Marshall Fund of the United States. That was after he spent three years as a senior fellow at the group’s Washington office.

Asmus was a US deputy assistant secretary-of-state for European affairs from 1997-to-2000. In that role, he helped former Communist nationals in Eastern Europe join the NATO alliance.

In 2002, Asmus wrote a book about that experience, called “Opening NATO’s Door.” Last year, he wrote another book about the war between Russia and Georgia from 2008. That book was called “The Little War that Shook the World.”