Well, this question has already been answered in a variety of forms . . . of course this depends entirely on what you believe. I believe India, China and Brazil will be the first countries to display evidence of Alien cultures and Full Disclosure as their mainstream media already regularly reports on Alien evidence.
America will have no choice but to follow along but should be leading the way however The Powers That Be still are insisting on keeping the public in the dark.
Ultimately this will backfire on them as it will become increasingly apparent they can't be trusted and may very well be the final stroke to their collapse.