I don't think we've had a justified conflict since WWII. I consider stopping the holocaust and Japanese atrocities in Asia to be just causes even if our government had other motives as well. I also think that fighting a war to abolish slavery was noble, even though it was horrible that it came to that.

When I was in the army, I thought they liberation of Kuwait was a legitimate reason, as was protecting innocent people from ethnic cleansing in Bosnia, but now that my son is serving there's no valid cause short of an invasion by a foreign military force.

Tacos.........................

Genocide, or ruthless dictaterships oppessing the masses. The list is long and the fine points can be argued, but it is a measure of our society.

I am not sure on how to best to answer this question as when I reply to topics such as this I always inadvertently offend someone
Here goes Ill speak my mind.

I have noticed that a few from 'over the pond' have mentioned 'Self Defense' as a reason for going to war. However in my experience expecting people to attack you ,creates a paranoia that breeds agression against the rest of the world. Take for example the USA. its whole culture is based on self-defence (British spelling) through FEAR. The latter is pumped into the minds of their citizens almost every moment of the day and fear of themselves, each other and espeically of ANYTHING that is not American and in many cases they see if It is not American then its not human or invalid. The latter describes a Jingoisitic attitude of which shows the USA'S war of aggression through FEAR (or poticially described as SELF Defence)

Almost every war since ww2 has been instigated either by USA meddling in affairs they are not equipped to do so such as; USA funding of the Taliban to fight the Russians and Supporting and giving AID to the IRA terrorists yet the latter the terrorists the USA DOES like trained the ones they DONT LIKE (See IRA/FARC/PLO/ETA/HAMMAS connections historical fact) Yet if you question most in the USA they view the IRA as freedom fighters, yet if one thought like that then one must assume ISIS are freedom fighters (you see how silly that thinking is?)

To sum up I am very wary when ANY COUNTRY claims self-defence is a reason to go to war.

War, to me, is to be a last resort. I wish that we could all get along and there to be no violence, but in my 52 years, I have see enough to know that it's never happened and it never will. I like that most of the time we do use sanctions and such to try to keep from war. Our government cherry picks where we get involved. We invade in the Gulf War while we ignored the war in Yugoslovia. why, that's a whole different thread. As bad as Saddam was, look at the mindset of the people who he had in his country and look what a mess we made.

Self defense of one's self from attack and the whole country from invasion.

Ethnic cleansing

Nothing. Only willing to defend against agressors. Going to war is always costing civilian lives.

Why? Who's asking?! I'll totally kick their ass!....but seriously, the world is a big game of Jenga...so much cause and effect...I can't actually say why I would go to war...the information would have to be there to show me that there was no feasible diplomatic way to deal with a situation that had to be dealt with....but I do want to join THE SPACE FORCE!!! I am so ready to kick some space ass!

Genocide type situation. Hitler killing Jews, the Czech conflict etc.

Any invasion or attack on our country or an ally self defense.

If you arent willing to fight or send your child into conflict then nothing is worth going to war over. Being a soldier who fought in Panama and was wounded there (my M.O.S. was 18delta) I can convey by first hand experience that war is hellish. Not to be engaged lightly by thought or process.

Nothing.
Instead of sending in people to fight for them, the leaders who want to wage war should have to fight each other. Then, when the fighting is over, and one emerges as the 'winner', shoot that bastard in the head-as a warning to the rest of the 'leaders'.

Coffee!

When you go to a restaurant and order a Deep Eddy's vodka tonic and they return with a brown-colored drink. I question it, and they say it is Deep Eddy's sweet-tea flavored vodka. Well, I tried it, handed it to the server and said, "Now THIS is the shit that should be in Leviticus."

The last slice of pizza!

Coffee.

killing or maiming my wife or kids / grandkids. that's it that's all.

Invasion of my own country or a close ally, I cannot justify being the invader.

My parents are both WWII survivors. One German, one French, they should have been mortal enemies. They taught me "you are NOT German, You are NOT French, You are NOT American, You are NOT white, You are NOT black , YOU ARE A HUMAN BEING!" if we all shred our nationalities, labels, & conformaties, and shared in the basic belief of social humanisim, there would be very little to fight. Still there is always greed- the worst trait of the the human charachter, the true basis of most wars.

Honestly, the lines are so blurred today that I don't know. I mean I know for sure if everything was "legitimate" that the reasons to go to war or protect yourself would be if another country attacked us militarily, attacked an ally, or performed atrocities on people that couldn't defend themselves. Even that can be blurred. Look at how the government lies and the media follows suit to go to war with some countries unjustifiably. The Gulf of Tonkin incident and Iraq are just two examples. I don't trust our government one bit. Is another country attacking us economically reason enough? We would be at war constantly if that was the case (we actually are constantly at war). Right now we would be militarily attacking China, Russia, Iran, or any other country that was against the petrodollar if that was the case. Has anyone in here heard any word on mainstream media about what's happening in Yemen right now with the U.S. help and Saudi Arabia?

It should be a last resort but I'll echo what some others have said: preventing an invasion, genocide or assisting an ally.

The threat of imminent war here at home. I'm not talking about the occasional crazy that slips through the cracks. We have far worse citizens here. I'm talking about a country that is mobilised and moving in for the kill. I am prepared to protect the homelands.
These oil wars however are atrocities in my eyes. Genocide committed by us.

If we are attacked by another country.

Defence from invasion, to stop genocide and the spread of dangerous ideologies / empires. Examples: WW2 to stop the spread fascism and the third reich and to end the holocaust. The cold war and its proxy wars to stop communism and the soviet union. The FIRST gulf war to expel Sadam from kuwait. The NATO intervention in Bosnia to stop the ethnic cleansing. Thats about it. The ISAF occupation of Afganistan, the Anglo-American invasion of Iraq in 2003 and whatever the hell we are doing in Syria nowadays were/are mistakes and shouldn'y have happend.

War is nothing but an excuse to heal a bruised ego. The powers that be if they would stop repressing technology and would concentrate more on education the world could evolve and become ready for the next step in human evolution.

Self defense would be the first thing I would pick. A nation has the right to collective self defense if being attacked and invaded by an enemy.