The Holy See has diplomatic relations with 180 nations, and its diplomatic corps is the oldest of all, going all the way back in some cases to the 5th century, and more formally since the 15th century. Today, the Vatican’s ultra-discreet diplomacy help broker deals between nations and has become a political tool that “packs a real punch.” The Holy See also has formal diplomatic relations with 16 inter-governmental bodies including the United Nations, the African Union, and the Organization of American States. There are a few countries that still do not have diplomatic relations with the Holy See, China, Saudi Arabia, North Korea, Vietnam, Afghanistan, and Bhutan.
While bilateral relations have been growing steadily from the 19th century, it was during the reign of John Paul II that it expanded from 85 nations to 174, including the addition of the United States in 1984, Great Britain in 1982, and Mexico in 1992. And while the Holy See is a “permanent observer” at the United Nations (not a voting member), it can participate in UN conventions, make speeches, and other functions that full members can do.
“The Roman Church is far-reaching in her plans and modes of operation. She is employing every device to extend her influence and increase her power in preparation for a fierce and determined conflict to regain control of the world, to re-establish persecution, and to undo all that Protestantism has done. Catholicism is gaining ground upon every side.” Great Controversy, page 566
Source Reference