If soldiers from one country physically invade the borders of another country and murders its citizens, is the invaded country justified in declaring war on the invading country?

If a country disrupts the flow of water, food, and natural resources of another country by rerouting rivers, blocking transportation routes, and enacting embargos on oil, etc. is the affected country justified in declaring war on the other country in order to get them to restores supplies and supply routes?

If a country mounts a cyberattack on another country, shutting down its computer systems, electrical grids, water purification systems, etc. would the attacked country be justified in declaring war on the attacking country to get the systems restored?

So far, what seem to be the conditions, principles, and motivations that justify a decision to go to war? Are there other situations in which a declaration of war against another country would be justified? How would a pacifist respond?

If country A invades country B, and country C provides country B with material support (such as aid money, weapons, etc.) is country A justified in declaring war on country C?

Is it ever morally justifiable to declare war and use force in order to protect and/or promote values?

Is it ever morally justifiable to declare war on a country that has engaged in evil? Darfur Aisha Duhulowa, 13-year-old girl who had been gang-raped and then sentenced to death by stoning by a Sharia court for fornication in Somalia.

Are soldiers who fight and sacrifice in an unjust war heroic? Minch’s argument: Heroism requires morality. Honor requires morality. An unjust war is immoral. Therefore, an unjust war fought by autonomous, rational moral agents means those agents cannot be warriors who are heroic or honorable. Therefore, only a moral war can be fought by heroes with honor.

All’s fair in love and war? Is it justifiable for a country to engage in a military attack that it knows will result in collateral damage if the attack is necessary to achieving critical military objectives? Who/what “counts?”

Military draft (“conscription”) abolished in Requirement that all men between the ages of register for draft abolished in In 1980, Soviet Union invaded Afghanistan, President Carter ordered the registration requirement be reinstated. Should the US every draft anyone into military service? Is it moral to initiate dangerous military actions using voluntarily enlisted soldiers, knowing that it is primarily low-income minorities who enlist?

Sex discrimination suit heard by U.S. Supreme Court in Court sided with the military: the male-only registration and draft was justifiable. Said purpose of draft is to raise combat troops. As women were excluded from combat, there would be no point in registering or drafting them. Women now serve in combat (by 2015 in infantry). Civil Rights Act of 1964 prohibits gender discrimination.

If we have solid evidence that there is a reasonable chance that torturing a prisoner during wartime will provide information that could save the lives of thousands of civilians, is torture justified?