Complex sentence: Hagelin is the president of Global Union of Scientists for Peace which is a coalition of leading scientists and experts, founded to prevent war, terrorism and nuclear proliferation and to promote safe, scientifically proven technologies for national security and global peace.
Split into simpler sentences: Hagelin is the president of Global Union of Scientists for Peace. The Global Union of Scientists for Peace is a coalition of leading scientists and experts, founded to prevent war, terrorism and nuclear proliferation and to promote safe, scientifically proven technologies for national security and global peace.