Nervous US and China-Russia ties
The White House seems to be have become a little nervous in recent years. It looks like some "minor annoyances", such as the setbacks of anti-government forces in Syria, former National Security Agency operative Edward Snowden's revelations, and some domestic problems, have pushed US President Barack Obama to take sharp steps and issue strong statements. Perhaps the developments have also prompted Obama to declare the United States' commitment to power politics, although he has used democracy and justice to justify such expressions.
The expos of Washington's surveillance program by Snowden didn't force the US to turn cold toward Russia. It was something more than that.
Russia, like China, does not share the White House's conviction that only Washington has the right to decide the fate of the world, and refuses to follow the US' dictates in international relations. The US is set to launch attacks on Syria, and in the process it would like once again to discredit its two main policy opponents, Russia and China, in the eyes of the American public and people across the rest of the world. The US aims to use the Snowden case - that Russia has granted him asylum - and the baseless accusation against China as an "Internet spy" to discredit them.