non-interventionist
adjective
[ ˌnɒnɪntəˈvɛnʃ(ə)nɪst ]
• favouring the principle of not becoming involved in the affairs of other countries.
• "a government practising non-interventionist policies"
non-interventionist
noun
• a supporter of the principle of not becoming involved in the affairs of other countries.
• "a nation of war-weary non-interventionists"