I'm not a teacher, but 'radical' conveys that your strategy is unconventional, unorthodox, somewhat unlikely or that you might not care about the possible consequences. 'Bold' on the other hand conveys that your strategy takes some courage to implement whether or not it is common to take such action. With a 'bold strategy' you raise the stakes in such a way that you might win in a spectacular fashion, or lose similarly.
I want to say "bold strategy" or "radical strategy" -- which one is better? I mean the strategy that is aggressive, with fundamental change...
"radical" is closer to what you describe. I agree with the above poster except for the "or that you might not care about the possible consequences". Usually radical people or people with radical ideas care very much about their policies.