[...] And why is there one rule for China and another for other nations?
Speaking at the same Senate hearing on May 13, US Assistant Secretary of Defence David Shear explained that:
Over the past two decades, all of the territorial claimants, other than Brunei, have developed outposts in the South China Sea, which they use to project civilian or maritime presence into surrounding waters, assert their sovereignty claims to land features, and monitor the activities of other claimants. In the Spratly islands, Vietnam has 48 outposts; the Philippines eight; China eight; Malaysia five; and Taiwan one.
So, despite being the largest and most powerful country among the claimants, China has, for many years, exercised a high degree of self-restraint.
And as Shear also said, compared with Vietnam and the Philippines, China is a latecomer:
Between 2009 and 2014, Vietnam was the most active claimant in terms of both outpost upgrades and land reclamation, reclaiming approximately 60 acres.
But have you ever read or heard of US criticism of Hanoi, or a US threat to send warships to deter the Vietnamese activity in the South China Sea? [...]