A. One should recognize the importance of health.
B. One should recognize importance of health.
Here, the first is right. Many differernt things can have importance, but here you are going to focus on one in particular- health, rather than justice, etc.
1 an expansion of NATO forces - here, he is asking for a single expansion, while the Postal Service could be exapnsion in more than one area. You could say 'the expansion' in the seond example because it is specific, like Bush's call. Bush is call is more specific than Karzai's because Karzai has called for it, but it hasn't fallen in general discussion yet.