Beijing would give Taiwan its strong backing if tensions triggered by the killing of a Taiwanese fisherman by the Philippine coastguard last week continue to escalate, analysts said yesterday.
But Beijing would express its support cautiously, they say, to avoid being seen as using the spat to step up cross-strait reunification efforts.
The foreign ministry and the State Council's Taiwan Affairs Office in Beijing have condemned Thursday's shooting in waters claimed by both the Philippines and Taiwan as part of their exclusive economic zones.
"We urged the Philippines to thoroughly investigate the case and furnish the details," foreign ministry spokesman Hong Lei said in Beijing yesterday.
Professor Xu Bodong, director of Beijing Union University's Taiwan Institute, said Beijing could possibly step up patrols in the South China Sea if the Philippines did not give a satisfactory reply to Taiwan.
Li Jiaquan, a senior researcher specialising in Taiwan affairs at the Chinese Academy of Social Sciences, said Beijing could also support Taiwanese sanctions against the Philippines.
He said Beijing's support would help lower Taiwanese people's resistance to closer ties with Beijing because "this will add positive sentiments to cross-straits efforts for resisting foreign intrusion".
There are rising calls for Taiwan and mainland to get closer to defend their common interests. For example, mainland activists have called for joint efforts with Taiwan to step up displays of sovereignty in disputed waters in the East China Sea also claimed by Japan.
But Taiwan's government seems wary of any mainland involvement in the row.
"So far we have not considered working with the mainland over the issue," Taiwanese foreign minister David Lin said.
He added that Taiwan had tried to discuss a fishery pact with the Philippines for a long time but Manila's concerns about Beijing's attitude had hampered any progress in the talks.
Shuai Hua-min, a legislator from Taiwan's ruling Kuomintang, said it would be more appropriate for the two sides to work on their own in defending their rights in the disputed waters.
Professor Alexander Huang Chieh-cheng, from the Graduate Institute of International Affairs and Strategic Studies at Tamkang University in Taiwan, said Taipei would not opt for co-operation with the mainland because "that would draw concerns from the United States, which does not hope for a cross-strait co-operation in disputed waters".
Xu Xue, a research fellow at Xiamen University's Centre for Taiwan Studies, said Beijing and Taipei are aware that any actions taken by mainland in the dispute could complicate ties between Washington, Manila and Taipei.