The Oxford Thesaurus An A-Z Dictionary of Synonyms - undermine v.

1) sap, drain, disable, weaken, debilitate, threaten, sabotage, subvert, damage, hurt, harm, impair, ruin, dash, wreck, spoil, Slang queer, bugger (up) : He said that the entire campaign would be undermined if the events of January 17th were ever revealed. 2) See undercut, 1, above.