fallen back on

Hence for the past 15 years America has fallen back on a two-track China policy.

因此过去15年美国对中国一直遵循一种双轨制政策。

As a result, more and more Palestinians have fallen back on family, clan, town and tribal loyalties.

因此，越来越多的巴勒斯坦人已回归到对家庭，族群，家园和部落的忠诚。