Despite the government’s posturing about its success in cross-strait and foreign policies, Washington is concerned about President Ma Ying-jeou’s (馬英九) linear approach, a national security expert said yesterday.

Liu Shih-chung (劉世忠), a researcher at the Taiwan Brain Trust think tank and a former aide to former president Chen Shui-bian (陳水扁), said Chen’s “zigzag” strategy made him unpredictable in ­setting policy during his two terms in office.