Wilbur Wright died in 1912, so he did not live long enough to see his invention used in wartime. But his younger brother, Orville, who lived until 1948, saw the plane's use both in World War I and World War II.
As you might expect, Orville's views on the use of planes in warfare changed over the years, as the way airplanes were used in battle changed. But throughout it all, he held a belief that the rulers and government officials of the world would be rational and avoid military conflict if the cost were too high. Through this reasoning, he believed airplanes would spur peace.
In October 1917, several months after the United States entered World War I, Orville did an interview in which he was asked if he and his brother thought that the airplane would one day be a factor in warfare. Orville replied that they viewed the airplane as "an instrument for the making of permanent peace" because in its scouting capabilities it would hinder troop movements, making the whole point of battle, so to speak.
From the start we saw in it an unerring scout through which armies could detect each other's movements. An army movement can be successful only if veiled int he strictest secrecy. We saw that the aeroplane would give eyes to armies ... [and] that when nations came to recognize what we saw, wars would end.
By the time World War I ended, Orville saw the destructive nature of airplanes, but hoped that their very destructiveness would compel nations to avoid war at all costs. He knew that airplanes could deliver "destruction by bomb and poison gas" and that this reality "has actually become a powerful instrument for peace." He reasoned, sensibly, that since airplanes could "drop bombs on the buildings occupied by the members of parliament and highest government officials" that no government would dare to start a war in the age of airplanes.
Orville held to this belief in the airplane's promise as a tool of peace through mutually assured destruction. Even after the US entered World War II, he wrote to Henry Ford reaffirming that "the aeroplane will be our main reliance in restoring peace to the World." World War II eventually did end with the dropping of two atomic bombs (from airplanes) on Japan.
If airplanes alone could not deter man from engaging in war, could the atomic bomb do so? In a letter in 1946, Orville wrote: "I once thought the aeroplane would end wars. I now wonder whether the aeroplane and the atomic bomb can do it. It seems that ambitious rulers will sacrifice the lives and property of all their people to gain a little personal fame." In the final interview he gave before his death, Orville shared his sadness that the airplane did not bring lasting peace. He admitted that he and his brother had "underestimated man's capacity to hate," and, referring to the United State's monopoly on the atomic bomb, he expressed "disappointment that through the airplane one country can go around threatening others with a new instrument of destruction."