1. They want what another country has šŗļøš¢ļø
Land. Oil. Water. Minerals. Even the routes that ships use to carry goods.
Countries need resources to grow. But sometimes, instead of trading or negotiating, their leaders try to grab what they want.
Take Iraqās invasion of Kuwait in 1990. Kuwait was a small, oil-rich country, and Iraqās leader Saddam Hussein wanted control over its oil reserves. Iraq also owed Kuwait a huge amount of money. Invading Kuwait was supposed to solve several problems at once.
Or take Venezuela, a South American country with enormous oil reserves. In January 2026, US forces captured its president, NicolĆ”s Maduro. The US accused him of serious drug-related crimes, but President Donald Trump also spoke openly about Venezuelaās oil.
The basic idea? Sometimes it's simply: "You've got something we want."
2. They want to be the boss šš
Sometimes a powerful country wants to control what other countries do.
When Russia invaded Ukraine in February 2022, President Vladimir Putin wanted to stop Ukraine from becoming too close to Western countries and their military alliance, NATO. Ukraine, meanwhile, wanted to decide its own future.
Itās like a bully deciding who someone else can be friends with ā except entire countries are involved.
Venezuela is another example. Trump wants America to dominate its part of the world ā North and South America or the Western Hemisphere. But Maduro wasnāt listening. Trump ordered an attack, US forces captured Maduro, and Trump backed his vice president, Delcy RodrĆguez, who took over and largely does what America wants.
It's the ultimate power flex ā with real people paying the price.
3. Theyāre scared of getting attacked first š”ļøš¬
Imagine two neighbouring countries. One buys weapons to feel safer. The other gets nervous and buys more. Soon, both fear an attack.
Political scientists call this the security dilemma: what makes one country feel safer can make another feel threatened.
Sometimes a country even strikes first because it thinks the other might become too dangerous.
In February 2026, the US and Israel attacked Iran, arguing, among other things, that it might develop nuclear weapons. Iran denied seeking them, but the attacks grew into a much bigger war.
The scary part? Sometimes fear prevents war. Sometimes it starts one.
4. They fight over land that feels like home š ā¤ļø
Imagine two groups who both see the same place as their homeland. Itās where their ancestors lived, where their history began and where they feel they belong.
Thatās one reason the IsraelāPalestine conflict is so difficult.
For Jewish Israelis, this is the land where their peopleās history and religion began thousands of years ago.
But Palestinians have also lived on this land for generations. During the war surrounding Israelās creation in 1948, hundreds of thousands of Palestinians fled or were forced from their homes.
And then thereās Jerusalem, a city sacred to Jews, Muslims and Christians, making the dispute even more emotional.
The big difference from point one? It's not just what the land is worth, but what it means to people.
When leaders turn such feelings into hatred or fear of other communities, conflicts can become even worse.
5. Leaders gamble. Ordinary people pay. š²š
Hereās the uncomfortable truth: whatās good for a countryās leaders isnāt always good for the country.
Some leaders may start wars to look strong, gain public support or stay in power. They might expect a quick victory ā and get their calculations spectacularly wrong.
Take Russia again. Putin apparently expected a much quicker victory when he invaded Ukraine in 2022. Instead, Ukraine fought back fiercely, and the war dragged on.
The reality check? One leader rolls the dice. An entire generation can pay the price.
6. Theyāre fighting back ā or say they are āļøš”ļø
If another country attacks yours, shouldnāt you be able to defend yourself? Even the United Nations recognises that right. Just war theory also says wars can sometimes be justified, but countries should seek peaceful solutions and protect innocent people.
But what if the attackers are militants hiding in another country?
In April 2025, terrorists killed 26 people near Pahalgam in Kashmir. India blamed Pakistan-linked militants and struck what it said were terrorist camps in Pakistan. Both countries exchanged military attacks before stopping on May 10.
Pakistan has made a similar argument about Afghanistan. It says militants based there attack Pakistan, so it has launched airstrikes across the border. According to the UN, over 1,100 civilians were killed or injured in Afghanistan in cross-border violence in 2026.
But hereās the twist: Pakistanās own military once helped train and support the Afghan Taliban, who now rule Afghanistan.
The big question? Even if you're fighting back, does that give you a free pass to do anything?