George Orwell taught us that all writing is political: Mary Lynn Bracht’s debut novel is forthrightly so. White Chrysanthemum is the story of two Korean sisters separated by the second world war. Hana is dragged away by a Japanese soldier to a life of sexual slavery; Emi is left to grow up wondering what happened to her sister. Hana’s narrative covers the war years, while in Emi’s chapters it is 2011, and the elderly Emi is still looking for her sister.

The language is blunt, with every page shouting of wrongs perpetrated. Bracht rejects the old mantra of show, don’t tell; her characters’ pain is shown, told, shown and told again. For example: “Anger and fear swarm through her body, radiating in hot waves to the soldier beside her. He stole her from her seaside home, from everything she knows and loves, and then raped her.” These events have already been described in detail, but Hana obsessively goes over them again in her mind. Indeed, the book forces us to confront the inescapability of these traumas.

Hana’s miseries are echoed in Emi’s quieter moments of pain. Bracht describes her parents pushing a flower into the ocean in mourning for their lost Hana: “It was a chrysanthemum, a symbol of mourning for Koreans. The imperial seal of Japan was the yellow chrysanthemum, a crest symbolising the imperial family’s power. Emi had wondered which came first, the symbol of power or mourning.” In 2011, Emi still cannot enjoy flowers. It is a reminder of the way our conflicts and sufferings seep into the future, changing the meaning of the most innocent of objects.

White Chrysanthemum gives glimpses of the suffering of others affected by the war – the Japanese soldier dehumanised by the starvation of his son and suicide of his wife, and the ageing Japanese “comfort woman” who is kind to Hana – but the bulk of the book’s attention and sympathy is for the Korean victims, the women whose stories are in danger of being lost for ever.

This book is fighting a battle that didn’t end with the surrender of Japan in 1945. It was only in 1993 that the Japanese government acknowledged the existence of comfort women; this despite the fact that the United Nations estimates that 200,000 women were forced into sexual slavery for the Japanese army. Most were Korean, although Japanese and Filipina women also suffered. In 2015, Japan’s government officially agreed to recognise its military’s use of comfort women and to set up a 1bn yen fund to help them; it did so only on condition that the Korean government consider the issue resolved and that the Statue of Peace in Seoul, which features a comfort woman, be taken down.

Even in late 2017, Japan and Korea were in talks reconsidering this deal. The Korea Herald quoted President Moon Jae-in saying many Koreans cannot “emotionally accept” this deal and Reuters reported that the Japanese foreign minister said: “We can by no means accept South Korea’s demands for additional measures.” It has recently been announced that Moon will not challenge the deal, but he still requests a heartfelt apology.

Bracht’s central concern is for the women whose stories are in danger of being lost for ever

At the end of White Chrysanthemum, Bracht includes a timeline starting with the end of the Korean empire in 1905 and continuing to the present day. Following that is a reading list of 38 books relating to the struggle of the comfort women. The book is fictional, but its concerns are political and historical; Bracht is writing in opposition to those who deny or minimise the atrocities committed against the women. Emi and Hana are stand-ins for the suffering of all Korean women taken and those left behind.

I suspect that the novel will affect readers differently, depending on their background. Speaking to a university-educated British friend, I discovered he hadn’t even known that Korea and Japan had fought each other. He’d never heard of the comfort women. For readers such as him, White Chrysanthemum introduces a heart-rending seam of history. Others I spoke to were aware of the war but were surprised to hear of the current tension. Bracht brings home the way that the suffering of Korean women in the 20th century still shapes lives today. For others still, the book may be a literary version of the contested statue. Bracht has fashioned her own memorial to the comfort women. White Chrysanthemum is a timely and furiously felt book.

• Rowan Hisayo Buchanan’s Harmless Like You is published by Sceptre.

• White Chrysanthemum is published by Chatto & Windus. To order a copy for £11.04 (RRP £12.99) go to guardianbookshop.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min p&p of £1.99.