politic

adj 1: marked by artful prudence, expedience, and shrewdness; "it is neither polite nor politic to get into other people's quarrels"; "a politic decision"; "a politic manager"; "a politic old scoundrel"; "a shrewd and politic reply" ant impolitic

2: smoothly agreeable and courteous with a degree of sophistication; "he was too politic to quarrel with so important a personage"; "the hostess averted a confrontation between two guests with a diplomatic change of subject"; "the manager pacified the customer with a smooth apology for the error"; "affable, suave, moderate men...smugly convinced of their respectability" - Ezra Pound syn smooth, suave

Source: WordNet. Princeton University