When a small kid is being bullied by a big kid in the block, an effective strategy is for the small kid to walk the neighborhood accompanied by another big kid. It works. Of course the small kid can go on his own, talk tough, learn martial art, and buy some weapons. But such actions could lead to a real confrontation, something the small kid must avoid.
The Philippines will benefit in many ways by strengthening its military alliance with the United States. The country is at a critical point of its economic development. It cannot afford to invest too much of its money on military weapons. It must buy time for its economic growth and aim to prosper to a level competitive with its East Asian neighbors.
The threat of military action by China against the Philippines should not be underestimated. China has a long history of warring with its neighbors. It fought Russia over a small island. It fought Vietnam over boundary issues, too. It sent many troops to fight in the Korean War. It had a bitter war with India.
The willingness of Filipinos to defend its territorial rights cannot be underestimated either. The last verse of its national anthem extols the joy of dying for the motherland. They fought hard during during WWII against the Japanese, and in Korea during the Korean War. But there should be no doubt the Philippines will be better off if its people don't have to die defending some islands.
The Filipino ego, typical of most Asians, is easily bruised. Preservation of honor is considered paramount. But Filipinos should learn from the Germans. Was it such a great dishonor for the Germans to have the US military presence in Germany until all of Germany was unified without war? US military presence bought them time and their moneys were spent on economic development. Today, Germany is considered the strongest economic power in Europe. The Philippines could be like Germany, albeit in East Asia, too.