Complex sentence: The latest US President to specify a list of countries with oppressive regimes was George W. Bush, whose 2008 Proclamation mentioned Belarus and North Korea, though in 1959 Belarus was denoted as White Ruthenia.
Split into simpler sentences: The latest US President to specify the list of countries with oppressive regimes was George W. Bush. Both countries were referred to in the, though in 1959 Belarus was denoted as White Ruthenia.