Vietnam's concept of national security is based on "the survival of the ruling regime that acts in the name of the country". Because the challenges to Vietnam's national security are perceived as challenges and threats to the ruling regime, the concept of national security tends to focus on the internal dimension of national security. The Mid-term National Congress of the Communist Party of Vietnam (CPV) in 1994 listed "four threats" facing the country, namely, the danger of falling behind neighbouring countries economically; the threat of "peaceful evolution"; deviation from socialism; and corruption and bureaucratism. None of them, except for peaceful evolution, comes from outside. Today, China is the only external threat to Vietnam's sovereignty and territorial integrity, and the focal point of that threat is the South China Sea. Vietnam has responded to this threat with a three-point policy: accommodating China's security interests; building up self-defence capability; and mobilizing international support. Recent serious challenges to Vietnam's national security policy include: the unpredictable politics of the United States over ratification of the TPP and uncertainty over its "pivot" to Asia strategy; President Rodrigo Duterte's tilt towards China, his country's "separation" from the United States, and the uncertain future of the U.S.-Philippines military alliance; China's strong reaction to the July ruling of the Permanent Court of Arbitration in favour of the Philippines, and a divided and weakened ASEAN.