The United States and China can't go on this way. As President Barack Obama meets President Xi Jinping in Washington this week, the world's two biggest economies are trying to rework their tangled relationship as partners and rivals — the frenemies of the globalized marketplace. Washington worries that Beijing will lose its nerve as its economy slows, backsliding on reforms meant to open the Chinese economy to foreign competition. The U.S.-China Business Council, which represents American businesses in China, complains that China denies foreign investors access to more than 100 industries. Conversely, the United States completely blocks foreign access to just five — nuclear energy; domestic airlines; customs brokerage services; credit unions and savings banks; and companies that issue bonds providing insurance on federal contracts — and restricts investments in 24 others."'Uncertainty' best characterizes the current view of American business leaders about China — uncertainty about China's economic slowdown, the leadership's commitment to meaningful reforms of its economy and the strategic issues in the U.S.-China relationship, especially cybersecurity,' " John Frisbie, the council president, wrote Monday in the group's magazine.