sit idly by

sit (idly) by

To stand aside and refrain from acting or intervening. They may not have broken the law themselves, but the CEOs certainly sat by and allowed these illegal activities to happen unchecked. I feel so guilty for sitting idly by while my son was going through such a difficult time in his life.
See also: by, sit
Farlex Dictionary of Idioms.

sit idly by

 and stand idly by
to remain close, doing nothing to help. I do not intend to stand idly by while my children need my help. The wealthy man sat idly by while the poor people starved.
See also: by, idly, sit
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • idly
  • sit (idly) by
  • sit by
  • sit on (one's) hands
  • sit on hands
  • sit on its hands
  • sit on one's hands
  • sit on your hands
  • stand (idly) by
  • stand by
References in classic literature
I cannot sit idly by and wait the great event that is his making, though he is not here to see.
But then again, we Filipinos lie down comfortably and sit idly by while all these are happening.
China's official news agency Xantha said: "The central govern-ment will not sit idly by and let this situation continue.
Talking about the National Accountability Bureau's investigations against him upon inquiry inside the court, he had said: 'The investigators ask me questions and then sit idly by, I urge the court to my 3 month remand to NAB so that their difficulties can be relieved.'
At this most difficult moment, when Taiwan and the DPP faced tough times, he could just not sit idly by and watch the party lose power and Taiwanese democracy lose its sovereignty, the former premier emphasized.
The Labour deputy leader said health professionals, policy-makers and the food industry should no longer "sit idly by" viewing obesity as a lifestyle choice.
'This means that anyone who tries to destroy RS must be aware that Serbia will not sit idly by,' stressed Dacic.
That shows me that Newcastle fans will not sit idly by and accept how Ashley is running their club.
This, the organisers said, is in view of his strong belief that central banks in developing countries cannot afford to sit idly by and concentrate only on price and monetary stability, given the enormity of their development challenges.
This precludes the fact that the duopoly of PLDT and Globe Telecom would just sit idly by.
"China doesn't want a trade war with the United States," Zhang said, adding that "But if the US takes actions that hurt Chinese interests, China will not sit idly by and will take necessary measures."
Are we as a country going to sit idly by and see yet another mass human cull creeping quietly through our own back doors, where resistance to such is not tolerated?
Unlike President Obama, I don't think Trump will sit idly by and do nothing to end the Syrian conflict.
"The world will not sit idly by as Europeans navel-gaze." --SPA 00:21 LOCAL TIME 21:21 GMT