What were Anne’s views about the futility of war?

During the lead-up to the war and her time in hiding, Anne Frank certainly heard a lot about the death and destruction that is caused by war. She reflects on this senselessness throughout the writing of her diary. She contemplates how the war causes everyone to suffer, not just the Jews.

All we can do is wait, as calmly as possible, for it to end. Jews and Christians alike are waiting, the whole world is waiting, and many are waiting for death.

We can see in her writing that Anne is very concerned that so many people are suffering because of the war. She blames politicians for wasting the lives of so many people. However, she also recognizes that this senseless bloodshed has something to do with human nature as well. It is the common person who actually takes part in waging war and inflicting harm on others. There is an innate urge to destroy and kill that exists in the soul of mankind. She feels that unless humanity as a whole can change, unless it can go through some sort of complete metamorphosis, war will continue to be part of the human condition.
This is not to say that Anne is a complete pessimist. She also writes about her faith in the goodness of people. She knows that other people are putting themselves at risk to help her and her family. However, it is difficult for Anne not to also contemplate the brutality of mankind, considering all that she is going through.

Anne is a seen as a sensitive person facing the usual problems of adolescence. Anne was of the view that war gave them nothing but only pain and tension. Everyday was filled with tension and sorrow. there were air raids and curfew was being imposed. People could not walk out freely. Anne was tired and sad of hearing the noise of bomb, people dying in pain. It is true from her dairy the feeling of concern she had for the Jews. Even though they lived in the same country still they were not able to hide from the annex and pain. this escape and freedom caused guilt as she could hear the pain and sufferings of the people. There were curfews outside and many people were killed. Thus her writing reflects her care and feelings towards her people.

In her diary entry for May 3rd, 1944, Anne reflects upon the futility of war. She really doesn't see the point of it all, and wonders, as so many others have done throughout history, just why it is that people can't live together peacefully. Anne thinks that people must be crazy for devoting all that money and all that energy to war instead of alleviating poverty and developing the arts and sciences.
Anne doesn't simply lay the blame for the war at the feet of politicians and capitalists; she thinks the common people are equally complicit. Otherwise, they would've rebelled against their leaders years ago. There's something in people, thinks Anne, that makes them want to go to war; a destructive urge to rage, murder, and kill. And until humanity experiences some kind of radical change, such primal urges will remain, and will always lead to wars and conflicts of one kind or another.