Thoughts on a Just War — John P. Kelly Ministries

Since 2025 began, Iran has launched countless missiles towards Israel, killing many citizens and requiring the nation to defend itself. However, the threat of Iran completing nuclear weapons with its uranium enrichment program was a bigger concern not only for Israel, but the entire Middle East (see Council on Foreign Relations). Since the early 2000s, most nations have been concerned about Iran’s intentions; notably, it has refused to let international inspectors into the nuclear facilities, broken agreements, and threatened other nations.

Most nations are aware that Iran has been funding terrorists to harm and kill Jewish people in Israel and around the world, and heads of State who stood with Israel and the Jews. The October 7, 2023, horror by Iran-funded Hamas terrorists and many other evil events escalated the need for a more powerful response to stop the aggression. After all attempts at diplomacy had failed between the nations, after numerous warnings issued, and offers to help establish peace in the region by the President of the United States, Donald J. Trump, Operation Midnight Hammer was unleashed on three of Iran’s nuclear facilities. It was a successful strategic strike on the factories, far from civilian towns.

Even though most people want peace, the subject of engaging in war has always been a difficult issue for many Christians. Is it biblical? Does God approve or disapprove of war? I have studied and prayed about this for years and now share my beliefs on the matter of a ‘Just War’ in the following two parts.

Part 1 of Just War: The Christian moral theory of Just War was established by three apostolic leaders, fathers of the faith, and theologians: Augustine of Hippo, Thomas Aquinas, and John Calvin. Each added an important piece to the puzzle. Their teaching on Just War was based on Jesus' teaching to love your neighbor as yourself. Therefore, the foundational morality of Just War theology and ideology is based on love.

When evil rises to commit mass murder or the threat of that happening is a possibility, then stopping it becomes an act of love. And failure to do so is a lack of love for your neighbor. It also lacks courageous faith. The bible tells us we are called by love to protect the innocent. Exodus 23:7; Jeremiah 22:3.

The issue has been debated and written about for centuries, including by early Christian leaders: Augustine, Aquinas, and Calvin.

One of the references for my position in favor of a righteous defense is from a modern-day theologian, Dr. Don Carson, co-founder of the Gospel Coalition. His extensive teaching on Just War does us a great favor by translating and combining the strict rules of war outlined by Augustine, Aquinas, and Calvin.

The first four strict rules govern the Why of going into a Just War. The last four strict rules govern the Conduct of Just Warfare.

1. The only just cause for going to war is defense against violent aggression.
2. The only just (right) intention is to restore a just peace to friend and foe alike.
3. Military force must be the last resort after negotiations and other efforts have been tried and have failed.
4. The decision to engage in such a just war must be made by the highest governmental authority; it is not a private matter.

5. The war must be for limited ends. (It’s to repel aggression, to redress injustice; not to exploit or colonize.)
6. The means of just war must be limited by proportionality to the offense. (This means if someone comes and bombs one of your cities, you don’t nuke the nation.)
7. There must be no intentional or direct attack on non-combatants.
8. War should not be prolonged where there is no reasonable hope of success within these limits.

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Part II of Just War: This part is to justify President Trump’s actions with Operation Midnight Hammer based upon the theological and epistemological principles of Augustine of Hippo, Thomas Aquinas, and John Calvin, who wrote about what constitutes a justifiable war and its warfare. Their confluence of thought was amazing; each added a piece of the puzzle on the topic of a Just War.

Even though the lives of these three men were separated by hundreds of years, they shared a common perspective on when Christians should and should not turn the other cheek, but instead respond with force. They especially wrote about how a nation should react to an imminent or actual invasion or threat of an imminent or actual genocidal act against a nation’s civilian population or an ethnic people group.

Regarding the defensive military actions taken recently by Israel and America against Iran’s military machine and nuclear facilities, we must judge them alongside the four strict rules that govern going into a justifiable war and the four strict principles regarding the conduct of justifiable warfare.

All eight of the Just War steps outlined above were amazingly followed perfectly by America, with President Trump leading the way as the Commander in Chief of the joint military forces of the United States of America.

This is an excellent example of how the strict rules of a Just War can be used to save lives and protect the innocent.

“Like birds flying about, So will the LORD of hosts defend Jerusalem. Defending, He will also deliver it; Passing over, He will preserve it” (Isaiah 31:5).