Why USA still do not want to take military action on North Korea despite N.Korea keep on threatening U.S and its allies?

Because the DPRK has always been threatening the US and allies without actually doing anything.

Also because it would involve harm to a lot of innocent people.

But conditions can always change, you never know.

South Korea not all that happy with USA and will soon kick them out.

China will just walk in and take over North Korea, install a Governor and re-unite North and South Korea.

Actually USA is threatening North Koreans. And the whole world nations who aim to be sovereign and independent.

I wiwl cwush the amewicans

If WE take military action, the whole world will turn against us as the aggressors. Tell me who wouldn't? But a war is inevitable unless we want to witness the slaughter of a million South Koreans. And it is obvious we can't wait five years. I recommend lobbing a few drones or rail gun shells across the North Korean peninsula until we goad them into attacking. I recommend then that we blanket bomb the 14 thousand pieces of artillery aimed at Seoul.

soon Iran will be testing and Israel have them from you whats the policeman going to do then you overplayed your hand in the world you are not good enough to rule it and the bomb will not allow a back down its a game no one can win you have put us in this game waving your stick all over the place we will all reap your whirlwind

If the US attacks North Korea without very good reason they risk war with Russia and China, as well as nuclear retaliation form the Norks.

If all parties against North Korea can agree a unified attack to neutralise North Korea then they should go for it.

The city of Seoul is within range of hundreds of hidden, protected artillery pieces North Korea has embedded in mountains on their side of the border. Any war between the North, South, and the U.S. will kill tens of thousands of civilians.

I'd suggest, and sincerely hope, that for once, somebody has a grip on Trump so he doesn't act before engaging brain. What kind of 'military action' do you suggest the USA takes? The moment they take action against N.Korea, UNLESS N. Korea fires first, and hits, that will involve China and Russia (both Communist countries too ) and then Iran, Syria and all the other countries only too keen to take a pop at the USA. And for once, I honestly hope we in the UK do not get involved much as if a nuclear bomb is involved, most of the Northern Hemisphere will be affected one way or another.