You don’t know which country, its random.
You cannot leave this island, you cannot end your life, you cannot abdicate your position.
Your country is immune from military attacks for 10 years, its literally impossible. There’s a magic force field protecting the entire island and the entire airspace up to 41,000 ft (max civillian flight level) and 12 nautical miles sorrounding the island. Enemy military are unable to enter.
You cannot get kidnapped or killed or like fall into a coma, or anything of the sort, you have plot armor for these 10 years. Any assassination attempts will magically fail.
Your population does not have plot armor they can die.
The enemy can send spies.
You get to choose the location of your island at the start. Things spawn in, and has a random amount of development of an average developing country, history, culture is randomly filled in and backdated. Everyone speaks your most fluent language and is literate.
You have zero nukes.
Aim for alliances with at least half the top militaries. If one is going to be gunning for us, I want their peers to have our back.
To that end, pick an island location with a strong command of shipping lanes, both to offer access to allies and to boost our economy. The invincible force field will help enforce this while we get set up. Offer temporarily invincible military bases to our allies - give them more reason to back us up, and hopefully jumpstart our military readiness.
Otherwise I’d go utopian like @Tonava said - entice the best and the brightest, and have them play to their strengths, aiming to have a robust, well-educated populace.