Depends. What war are you talking about? If it's WW1, then it's because everyone was stupid at the time and thought their enemies did it and one thing led to another.
Two inventions from the World War two are the radar and the sonar, both of which had a huge impact in the war, but also after it, becoming a widely used devices all over the world.
The radar was an invention that was enabling detection of objects in the air. Initially it is was used for detection of planes, as that's where the biggest threat was coming. This device enabled the soldiers and the civilians to be warned about the oncoming danger, but also to be able to respond adequately to the threat.
The sonar was another invention inspired by the war. It had the same basic purpose as the radar, just that it was used for detecting objects in the water. This was a crucial instrument that gave the submarines big advantage in locating the enemy and destroying it, or if not capable of that, being able to move away and avoid it.
Answer:
Because we all need each other's strength and support
Explanation:
Hope this helps
Federalism
Federalism is the mixed system of government, combining a central government with regional governments in a single political system. By combining the various states into the general central government, the power of the national government increased making it strong enough to deliver
