Gone are the banquets extolling the 'golden age' of Sino-Philippine relations that had marked the past decade. Instead, relations today have sunk to an all-time low with armed vessels from both states staking out Scarborough Shoal - a tiny atoll in the South China Sea that sinks at high tide except for one rocky outcrop - which both say is theirs. What has caught the world by surprise is the refusal of the Philippines - whose most powerful warship is a second world war-vintage former US destroyer - to cave in to China's demand to leave the atoll 220 kilometres west of Luzon, even if the face-off was described by former Philippine foreign minister Domingo Siazon as 'between an elephant and an ant'. Observers point to three main reasons for Manila's tougher stance towards Beijing. Foremost was the sea change in Washington's attitude to getting involved in the South China Sea dispute, Ramon Casiple, executive director of the Institute for Political and Electoral Reforms told the South China Morning Post. He noted that last year the US announced that Asia would be the fulcrum or pivot of its foreign policy. 'This places the Philippines in a geo-strategic role. Remember, the presence of US bases here gave the US a strategic advantage in conducting its wars in Vietnam and Korea.' He added: 'As China raises the ante, the Philippines has no choice but to strengthen US ties.' Yesterday, in ceremonies marking the end of the yearly Balikatan military exercises involving US and Philippine forces, Manila's military chief Lieutenant General Jesse Dellosa told US Ambassador Harry Thomas: 'As we bring our shared history of co-operation into the future, it is paramount that we agree on synchronising our structured responses, protocols and mechanisms to scenarios and situations in areas of common concern and mutual interest.' Teresita Ang See, president of the Philippine Association for Chinese Studies and an influential leader in Manila's ethnic Chinese community, believes Washington has encouraged Manila's defiance. 'I really see the US hand behind it,' she said. The second factor was the belief by Philippine officials that China was bent on grabbing territory from Manila because of possible oil and gas deposits. 'If we don't watch out, Scarborough Shoal could go the way of Mischief Reef' which Beijing seized from Manila nearly 20 years ago, warned Lauro Baja, a retired Philippine permanent representative to the United Nations. 'We failed to take what I call aggressive action then,' Baja told the Post as he expressed regret over what had happened during his watch. This lesson is not lost on the present government. A senior government official who spoke on condition of anonymity said: 'This is not being bold. We are doing what any sovereign government would do when its territory is being encroached upon by another country. Any self-respecting government would do the same.' The official added: 'The truth is, there's nothing in the Spratlys [or Nansha islands also claimed by China] but coral and endangered beautiful fish. There are no oil resources there. 'The resources are in Recto Bank which China started claiming only after the previous administration [of former Philippine president Gloria Macapagal-Arroyo] entered into a Joint Marine Seismic Undertaking with China in 2004,' he said. Today, the administration of President Benigno Aquino is tendering 15 oil exploration contracts. Of these, two blocs were part of the area once covered by the undertaking, Energy Undersecretary Jose Layug confirmed. He stressed, though, that these were in northwest Palawan and well within Philippine territory. He said bids for both blocs would be awarded by July 31, despite China's protests earlier this year at the inclusion of these areas. Finally, two sources pointed to 'cultural nuances' behind the current stand-off. Unlike former president Arroyo, who was very comfortable dealing with the Chinese, Ang said Aquino was more at home with the Americans. 'He spent the best years of his life in the US. He will not exchange his hotdogs and pizza for siopao [steamed buns] and misua [noodle soup].' Casiple agreed that both leaders had different perspectives on the Chinese. 'Remember that GMA [Arroyo] had strong Chinese connections.' As a student, she founded the Philippine-China Understanding which pushed for diplomatic relations with Beijing. In contrast, he said, Aquino lived for some time in the US and the presidency of his mother, Corazon, was saved from a coup attempt by the US.