idly, stand by

ねてxxx(みかねてxxx) Can’t stand idly by while this bad thing happens, so you did xxx to solve the problem. Unlike たまるか or 勘弁できない!、見兼ねて is NOT used in anger. 見兼ねて is more like, “I couldn’t stand to see that abandoned kitten in the rain, so I adopted it.” Or “I couldn’t stand to see Grandma in such pain, so I checked her into the hospital.”
(みごろし) To deliberately stand by and ignore a dying/ suffering person.
ない(かんべんできない) Very close to 我慢できない! But with a narrower meaning. I can’t stand it any longer!! This is the one to use about politics.
たまるか More than “I can’t stand idly by.” More like, “I won’t stand for it! I can’t tolerate it! more closer to” xxxものか!” than 見兼ねて. This is the one to use when you are beyond just words. Like when you are going to physically step in front of a person to stop them from executing their evil deeds.
Can’t stand idly by (while this horrible thing happens)