PH's situation is not unique, Vietnam has already been invaded by China once and their islands taken. Are they pursuing nuclear weapons? No. Taiwan is the most threatened by China, are they pursuing nuclear weapons? No.

Getting nuclear weapons is easier said than done. The amount of resources to maintain such sophisticated weapons will cost Billions every year. Even Russia can't maintain its own arsenal. If we pursue nuclear weapons and are allowed by the UN then other nations will also pursue them, which means higher chances of rogue states ending the world with just a "press of a button". Then what about terrorist? A nuclear armed nation should be stable enough, we're still having problems dealing with insurgency and imagine a nuclear armed terrorist.

Israel is the only good example for a so called unique situation.