It’s fortunate that liberal democracy, the only acceptable sort of governance (because it’s the only one that respects the dignity and rights of the individual) is also the one that is most conductive to greatness. Not necessarily greatness of the nation, but of the individual and of business and other organizations. From this, national greatness sometimes results.
Alex Tabarrok has a related article about how democracy and capitalism are mutually reinforcing.
Nehaveigur 