South China Sea: Why are China and Philippines tensions heating up?

An escalating diplomatic row and maritime incidents between China and the Philippines have heightened tensions in the South China Sea. China's assertive claims over disputed features within the Philippines' exclusive economic zone, despite an international court ruling against them, have led to confrontations, including dangerous encounters at sea. International condemnation of China's actions has prompted the Philippines to adopt a firm stance and seek support from allies like the United States and Japan, while refraining from invoking the Mutual Defense Treaty to avoid escalating the conflict.