The Collaborative International Dictionary of English v.0.48:

noninterference \noninterference\ n.
   a foreign policy of staying out of other countries' disputes;
   nonintervention.

   Syn: nonintervention.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

noninterference
    n 1: a foreign policy of staying out of other countries'
         disputes [syn: nonintervention, noninterference] [ant:
         interference, intervention]

Moby Thesaurus II by Grady Ward, 1.0:

63 Moby Thesaurus words for "noninterference":
   autarky, bimetallism, capitalism, culpa, culpable negligence,
   default, dereliction, disregard, economic self-sufficiency,
   failure, free competition, free enterprise, free trade,
   governmentalism, inadvertence, inadvertency, inattention,
   isolationism, laches, laissez-aller, laissez-faire,
   laissez-faireism, lapse, laxity, laxness, let-alone policy,
   let-alone principle, liberalism, line, localism, looseness,
   managed currency, neglect, neglectfulness, negligence, nonfeasance,
   nonintervention, nonperformance, nonrestriction, nullification,
   omission, overlooking, oversight, party line, party principle,
   permissiveness, planned economy, policy, polity, poor stewardship,
   position, price supports, procrastination, protection,
   protectionism, public policy, pump-priming, remissness,
   sectionalism, self-regulating market, slackness, slight,
   unrigorousness