It seems that China is determined to bully the Philippines when it comes to the Scarborough Shoal issue despite diplomatic efforts to resolve the impasse. I'm not an expert on international law and foreign affairs but logic dictates that the option left for the country is to invoke the RP-US Mutual Defense Pact. Under said treaty, both the United States and the Philippines have committed to defend each other in times of threat from external aggression.
I might sound exaggerated or one might say that it is still premature to go that far but the Philippines should send a clear signal to China that the Filipino nation is determined to assert its sovereignty and in so doing, it should exhaust all available resources and avenues to stand-up against a bully neighbor. A show of force by the Philippines by requesting the United States to deploy one of its aircraft carriers might make China re-think of its position.
Invoking the RP-US Mutual Defense Treaty should not be construed as being too dependent on the United States, because the Philippines and the US are supposed to be allies. China, an emerging superpower should abandon an expansionist policy.
