Obama has rationalized his actions by saying he can't tell foreign leaders that he has to wait for the US Congress.
This reveals two key things about Obama:
1) He believes that he has total power and that the peoples representatives in Congress have none.
2) Offending foreigners is a worse crime than ignoring the American people.
Just more evidence that Obama has the heart of a tyrant not a president. That's why he's more comfortable with dictators like Xi Jinping than with the American people.