“In order to make an omelet you have to break a few eggs” is a proverb that teaches that there are circumstances in which you have to make some sort of expenditure or sacrifice to gain something, make progress, or improve your lot in life.
“The generals realized that if they were going to take the island of Iwo Jima from the Japanese, that it would result in bloody sacrifices and many causalities. It was an example of to make an omelet, you have to break a few eggs.”
I bet this English proverb may not directly translate into a proverb in Chinese. How would Chinese convey this concept?