NEW DELHI — The repression let loose by Burma's (Myanmar) military junta has fittingly drawn international outrage. But the indignation and new wave of U.S.-led sanctions also obscure an inconvenient truth: Promotion of freedom has become a diplomatic instrument to target not China — the world's biggest human-rights abuser — or a Russia sliding away from democracy, but rather weak, unpopular and isolated states.

Look at the paradox: The principle that engagement is better than coercion or punitive action to help change state behavior is applied only to powerful autocratic countries, while sanctions are a favored tool to try and tame the weak.

Another irony is that the more you punish and isolate a scofflaw state, the more the big bad states gain strategically and commercially. Nothing better illustrates this than the way Beijing has signed up tens of billions of dollars worth of energy and arms contracts in recent years with pariah regimes stretching from Burma and Iran to Sudan and Venezuela.