Thanks for the chance to help. I am an attorney with over 12 years military law
You have to concern yourself with US tax law. As a US Citizen, you are subject to US tax law. So you will need to file taxes with the US Government.
However, if you are no longer on active duty, and are moving to an overseas location, then you will not have to file state taxes UNLESS you have business or property in a particular state.
State tax law is tied to residence.
You are correct that since you joined in FL, and maintained residence in FL during your service, you were proper to file in FL.
But now that you are retired, and not living in FL, you will not have a duty to file in FL or any other state.
The exception will be if you own property or a business in one or more states...in such a case you may be required to file in that particular state.
But short of that? There is no requirement to file a state tax return if you do not live in the state.