The U.S. naval challenge to China's territorial assertiveness in the South China Sea this week came after months of frustration within the Pentagon at what some defense officials saw as unnecessary delays by the White House and State Department in approving the mission.
As early as mid-May, the Pentagon was considering sending military aircraft and ships to assert the principle of freedom of navigation around China's artificial islands in the Spratly archipelago after Defense Secretary Ash Carter requested options to respond to their rapid construction.
That patrol eventually took place on Tuesday when the USS Lassen, a guided-missile destroyer, sailed within 12 nautical miles of Subi Reef, triggering an angry rebuke from China and threatening to ratchet up tensions between the world's two biggest economies.