I've always been confused when it's proper to use the word "the" when describing or referring something. Here's an example: "I would really like to know what caused the Titanic to sink so fast" Or "I would really like to know what caused Titanic to sink so fast" Which is proper? Here's another one that puzzles me; "My father works for the CIA"as opposed to; "My father works for NASA" It's common to hear someone refer to "the CIA" But, I never hear anyone refer to "the NASA". What gives here?
But what about 'The' for Countries
'The Vatican' is a shortening of an older official name, the Vatican States, like the US or the UK.
'The Ukraine', 'the Levant', 'the Sinde' are British designations that applied when those were areas rather than countries, or are now provinces within a country. Indeed, there is an official move to say Ukraine rather than 'the Ukraine' in recognition that Ukraine is a separate country, not a part of Poland or 'Little Russia' or an SSR/CCP.
But what about 'The Wirral' Or "The Netherlands", as well as many nations comprising groups of islands, like "The Philippines", etc.
Yes, it does look like, if an abbreviation is pronounced as set of letters (FBI - ef b iai) then this word needs an article. In the other case (NASA - naesa) the article isn't needed.
Other examples are the CIA, the NIS, the IRS, the WTO, the EU -- and then NAFTA and NATO. If the abbreviation is not the name of an organization this rule does not necessarily apply.