undermine-sap-weaken

These limitations may undermine the health care system.
这些限制可能会损害医疗保健制度。
Years of failures in the elections have sapped him of his confidence.
连年竞选失败使他逐渐丧失了自信。
sap的本意：在……下挖掘;逐渐侵蚀（或破坏）……的基础;挖坑道逼近（敌方阵地），在……下挖坑道;挖……的墙脚

The children were weakened by lack of essential nutrients for a long time.
那些孩子因为长期营养不良而身体衰弱。