Typhoon / Charles Cumming.

Enhanced descriptions from Syndetics:

Charles Cumming, lauded internationally as the successor to John le Carré, returns with his biggest, most ambitious thriller to date. Beginning in 1997, just as the British are about to re - turn Hong Kong to Chinese rule, Joe Lennox, a young opera tive for SIS (MI6), loses both his girlfriend and his first high profile asset--a prominent defector who disappears from a safe house. The girlfriend he lost to Miles Coolidge, a hard-bitten CIA agent; the asset to collusion between his bosses and the CIA. Over ten years later, during the run-up to the Beijing Olympics, Lennox is back in China, facing his old nemeses. With the CIA plotting to use an Islamic group to destabilize China, the SIS seeking to thwart them and his old asset the key to all of this, Joe Lennox, Miles Coolidge, and the girlfriend they shared are all hopelessly intertwined in a plot where trust is impossible and truth is unknowable.