Philippines inherit USs political or maybe legislation system, so they can only rely on US.
First, Taiwan's military strength and expenditure both surpassed Philippines far away, from this point, TW is an important customer of US. As for Philippines, we all know her military strength....Just an old little patrol boat with 50 years old does not even mean Philippines is an arms customer of US.
Second, I won't comment so much on TW, but from a mainlander, I have to say, we never take TW as an enemy, at least from the bottom of heart, neither could there be a war between China and TW. I do not think TW faces such severe threat. Her only enemy is Philippines. Now relying on China mainland's huge market and language advantage, TW has benefited a lot from China. China with a rapidly economic growth would be an important market of TW, without China's business friendly bureaucracy and privileges specified for TW businessmen, TW's economy will be stucked into an adverse situation. The current situation is that TW depend more on China and TW has a growing trade surplus every year towards China, which means they are making money. China can provide more economic opportunities for TW than US can. TW will have a sustainable growth without US.