Pacific region faces a period of strategic tensions that could damage economic ties as key national players adapt to an increasingly assertive China growing impatient with US efforts to shore up its influence. The Nov. 13-14 Asia-Pacific Economic Cooperation (APEC) summit in Japan, coming on the heels of a gathering of G20 leaders in Seoul, will test how much regional powers allow those strains to overshadow efforts to show collective goodwill. Warning shots fired Wednesday by South Korea's navy to drive away a North Korean fishing boat at a maritime border were a reminder of tensions in a region where Pyongyang is a persistent threat to stability. No one is predicting a shooting war in the world's fastest growing economic region, but experts warn the danger of unintended military clashes has risen as Beijing tries to extend its naval reach and ties chill with rival Japan. Security tensions could also spill over into trade and investment, while rivalry over resources from oil and gas to rare earth minerals risks fuelling strategic conflicts in turn. “It could well turn out that after another 12 months of this, everyone pulls back and settles down and new lines are drawn ... But I don't actually think that is going to happen,” said Alan Dupont, a professor at the University of Sydney's Center for International Security Studies. “I see this as the beginning of a more volatile period strategically in East Asia.” Sino-Japanese relations have taken a sharp dive due to a feud over claims to isles in the East China Sea near potentially huge maritime gas and oil reserves, just as a vibrant China grabs stagnant Japan's No.2 world economic ranking. US-China ties have been strained by currency and trade rows and Beijing's push to expand its sphere of influence. Aides to President Barack Obama, who heads to Asia Friday after his party's devastating defeat in US elections, will raise the issue of what Washington says is China's undervalued yuan currency when he meets Chinese counterparts. Russia also leapt into the fray this week when President Dmitry Medvedev visited part of an island chain north of Japan claimed by both countries, sparking another row with Tokyo. Until recently, China's rapid economic growth was seen by many as a force for stability, but now its economic strength allied with big military spending is prompting second thoughts. “The only thing we had before was the economic intertwining, and we know from experience prior to World War I that this does not guarantee stability,” said Andrew Horvat, director of the Stanford Japan Center in Kyoto, western Japan, although he played down any view of East Asia as a military powder keg. Tokyo, Washington and Southeast Asian nations have grown increasingly wary of China's intentions as it spends heavily to modernize its military, sends its navy further afield and asserts sovereignty over the contested South China Sea.