Security, economics and the environment were the key topics for US presidential candidates John McCain and Barack Obama as they offered insights into how US-China relations would be managed under their respective administrations, Reuters reported. The candidates laid out their views in position papers published on Monday by the American Chamber of Commerce in China. Obama said a "change in currency practices" is central to redressing Washington’s trade deficit with Beijing. He accused China of maintaining its currency at an artificially low rate and pledged to back legislation that defined currency manipulation as an illegal subsidy, which would enable the US to impose duties on more Chinese goods. McCain accused Obama of "preying on the fears stoked by Asia’s dynamism," although he did say China must fulfill its obligations on currency issues, as well as enforcing international trade rules, protecting intellectual property and lowering manufacturing tariffs.