The following nations all have something in common: Antigua and Barbuda, Azerbaijan, Belize, Bolivia, Cambodia, Colombia, Cook Islands, Dominican Republic, El Salvador, Georgia, Israel, Ireland, Kiribati, Laos, Liechtenstein, Marshall Islands, Mauritius, Monaco, Nicaragua, People’s Republic of China, Philippines, Republic of China (Taiwan), Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, San Marino, São Tomé and Príncipe,
Saint Thomas, Saudi Arabia, Seychelles, Solomon Islands, Tunisia, United States of America. What is it?
EDIT: Saint Thomas is the name of one of the United States Virgin Islands, a non-self governing territory of the United States of America, and therefore does not qualify for inclusion on the list. Not A Potted Plant regrets the error.