"Pictures to hurt you": A war photographer's final testament to Vietnam

"I want my pictures to hurt you, I don't want you having any free rides, I'm there to upset you and I'm there to make you feel uncomfortable the way I feel when I go to bed at night, otherwise there's no point in me going in the first place."

That is what legendary British war photographer Sir Don McCullin told CBS News ahead of the publication of what he says will be his final book.

For more than 50 years, McCullin covered conflicts across the world, from Cyprus, Biafra and Israel to Lebanon, Afghanistan and Northern Ireland.

Now the 90-year-old is preparing to publish a powerful retrospective of a conflict that defined both his career and a generation: "Vietnam."

The book draws from thousands of images McCullin captured during multiple assignments in Vietnam during the 1960s and early 1970s.

Some of McCullin's most iconic work features alongside a selection of never-before-seen photographs, documenting horrors that continue to resonate deep in the American psyche.

Unflinching and raw, the pictures capture not only the violence and pain suffered by innocent civilians caught in the crossfire, but the gnawing fear and exhaustion of the U.S. Marines with whom McCullin was embedded.

At the heart of the new book is the 1968 Battle of Hue, fought during the notoriously bloody Tet Offensive. "It was amazing any of us survived," McCullin told CBS News correspondent Charlie D'Agata at his home in the rolling hills of southwest England.

"I was told by a senior officer that there was going to be a 24-hour operation, and you know, 11 days later I was still there."

It was in the ancient city of Hue that McCullin took arguably his most famous photograph — one that became one of the most defining images of the Vietnam War.

"Shell-shocked US Marine" is as haunting as it is simple: A soldier, motionless and apparently unresponsive, sat clutching his rifle and staring blankly into the distance.

"I made five frames of this soldier sitting there and not once did his eyelashes move. Every one of those frames is identical," McCullin said.

"Frankly, I hate this picture, because people think it's the only decent picture I've ever taken."

"It's just that you have to be careful when you make these pictures," he added. "If you turn them into an iconic picture and they are bearable to look at, you haven't done your job properly because it means that people will accept instead of turning away."