From the earliest days of civilization, people have fought with each other. And as they organized into tribes, and eventually countries, the fighting continued, with people waging countless wars for countless reasons. Sometimes a country wants to take another's territory or resources, or it may want to change how another country is governed. Some countries go to war to protect themselves from perceived external threats. If country A believes country B is about to attack and poses an imminent threat, country A might decide to strike country B first.
This is called a preemptive war, and under international law, it is considered to be legitimate and lawful. A similar but less legitimate reason in the eyes of the law is a preventive striker war, meaning country A believes country B poses a gathering threat and wants to prevent that threat from becoming a reality. While countries might have multiple reasons to start a war, they're often deterred, that is, discouraged from doing so by the likely price they would pay. Country A might want to attack Country B, but realizes that Country B has a powerful enough military to seriously harm Country A. So Country A does not attack B.
Or maybe Country B doesn't have that much military power, but Country B has an alliance with Country C, meaning that it would come to Country B's aid if Country A ever attacked. Country A might then believe that the combined power of countries B and C could seriously harm country A in a war, so A chooses not to attack. When countries form alliances or build up their military capabilities and signal that they're willing to use them in collective defense, this can strengthen deterrence. If deterrence is robust, their adversaries are less likely to attack them because of the cost and risk of doing so.
At the same time, alliances can also be used for aggressive purposes, as was the case in the lead-up to World War II, when Germany, Italy, and Japan formed an alliance, not to preserve the international order, but instead to protect it. to overturn it and forcefully expand their control. That war ended with the introduction of nuclear weapons. They're often referred to as the ultimate deterrent.
And no nuclear power has ever waged a full-scale war with another nuclear power. During the Cold War, tensions rose between the United States and the Soviet Union. It was the unprecedented power posed by nuclear weapons and the threat of mutually assured destruction that deterred the two countries, preventing their power struggle from boiling over, keeping the Cold War cold.
Deterrence, though, isn't foolproof. Wars between countries still do occur, and could continue to occur in the future. But they've become far less common.
And instead, wars within countries, or civil wars, have become far more common. There are generally two types of civil wars. One is a war of secession, where one group within a country fights to secede, or break away and form their own separate country.
The other is a war of succession, where groups within a country fight to change who is in power, or how their country is governed. Both types of civil conflict thrive in weak or failed countries, where a government has lost control of what happens within its borders. Corruption is widespread, levels of inequality are high, and there is an extreme concentration of violence. power, and both can have implications far beyond a country's borders.
Civil conflict and instability make it easier for terrorist groups and organized crime to set up operations in a country, and can create huge flows of refugees. affecting countries throughout the region and around the world. Such instability also makes it harder for countries to collaborate on global challenges like climate change and pandemic containment.
Civil conflicts can also serve as proxy fights for larger, more powerful countries to compete against each other by supporting opposing sides. It's a situation which can raise the stakes and blur a conflict's original motivations. And in modern countries, conflicts, soldiers might not have uniforms or guns, and might not actually be on the battlefield. Today, war is often fought in unconventional ways, involving non-state actors like terrorists, or taking place in cyberspace.
And as conflict evolves, traditional tools of deterrence become less powerful, and order becomes harder to maintain. Many terrorist groups aren't necessarily deterred by a country's military or economic might, because they typically don't have their own country or territory that can be retaliated against. And when a country or an organization attacks another country with a cyber weapon, it is hard to immediately know how severe the attack is, where it came from, and who is responsible. This undermines deterrence. Looking back, the beginning of the 20th century saw two devastating world wars.
The first, which claimed the lives of 20 million people, and the second, which killed around three times as many, and was the deadliest conflict in human history. Since then, conflict has continued to evolve. but human nature and the reasons why countries and people fight remain relatively unchanged.