S.J. Friedman is the author of the book "Silenced No More: Voices of Comfort Women." The opinions expressed here are solely hers.

(CNN) After 70 years, the Japanese and South Korean governments finally released a joint statement outlining a bilateral agreement to settle the issue of comfort women, a euphemism for girls and women forced to have sex with Japanese soldiers from the 1930s until the end of World War WII.

The agreement states the Japanese government will offer a one-time final apology and to pay 1 billion yen ($8.3m) to provide care for victims through a foundation.

While there are those who argue that this is a breakthrough for the comfort women movement, the longest running activist movement on sex slavery in modern history, this agreement only deals with one country -- the reconciliation between Japan and South Korea.

It doesn't begin to address the fact that other nations continue to hold a similar grudge against the Japanese government.

In the past few days, other government leaders have begun to speak out. Taiwan's President Ma Ying-jeou called on the Japanese government to apologize and extend compensation to Taiwanese women used as wartime sex slaves.

Estimates

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Academics have estimated that 200,000 women and girls across Asia Pacific were forced into sexual slavery by Japan's military. While up to half of these victims were estimated to be from Korea, there were many other victims from China, Taiwan, Netherlands, Philippines, and Indonesia who were also systematically used as sex slaves by the Japanese Imperial Army.

The leading scholar in China on comfort women, Su Zhiliang, of Shanghai Normal University, told me the number of victims may be much higher -- 400,000 -- with 200,000 Chinese women forced to work as unpaid prostitutes.

He calculated this figure from the approximately 1,000 military brothels that were managed by the Japanese government and military. Each year in China, more women find the courage to come out and tell their own story.

During research for my book "Silenced No More," I interviewed dozens of women from China and other countries who had been forced into prostitution. Like their Korean counterparts, the period of captivity they experienced destroyed their lives.

Many of them suffered from severe post-traumatic stress syndrome.

They faced debilitating physical and emotional problems that prevented them from living normal lives.

The first Chinese survivor to speak out, the late Wan Aihua, was 15 when she was captured, tortured and repeatedly raped. Wan had fainting spells whenever she recounted her experiences during the war. Even in her old age, she suffered great physical, emotional pain, and was unable to marry and have children of her own. She eventually adopted a daughter.

Wan Aihua was the first Chinese survivor to testify in public in China. She was from Shanxi, a province where many of the victims were from -- Hainan being one other prominent origin.

Sincere apology

These victims deserve a sincere apology that brings healing and official restitution.

Aren't their needs for reconciliation just as important and relevant as their Korean counterparts? Shouldn't their governments also be seeking a similar apology and compensation for their victims?

If the Japanese government and prime minister issue an apology for Korea, this same process must be carried out in the other countries where women suffered the same fate. These women also want the Japanese government admit legal responsibility for what really happened with a strong, sincere voice that offers them the dignity and respect they deserve.

So important is this issue to the Chinese government that in December 2015 they opened a museum in Nanjing that focuses solely on the plight of comfort women.

During the inauguration, a handful of adopted children of Chinese survivors attended on behalf of their mothers who had passed away. The museum was set up create awareness of this human rights tragedy and as a way to honor the comfort women and their legacy. It also seeks to prevent similar sexual violence in military conflicts around the world.

Closure of these war wounds is urgently needed for all those involved. This reconciliation will help to heal both the victims and perpetrators alike, as well as for the nations involved.

Even after 70 years, feelings of animosity and hatred still prevail among the Chinese against the Japanese. If this is not addressed, it will continue to be passed down from generation to generation. To break this cycle, an apology would bring about healing and help facilitate a grassroots reconciliation process.

Wartime sexual slavery today

The voices of elderly survivors of Imperial Japanese military sex slavery have roused people to identify with their suffering. The breaking of their silence was a heroic act.

They could have kept these secrets do their grave. But instead, to prevent it from happening again, they had the courage to stand up for others.

The elderly survivors have left a legacy of moral courage and human rights activism. What happened to these women must be remembered.

We must reflect and understand the universal lessons from these crimes against humanity and see that they do not happen again. We need to also learn from this chapter of history. This form of exploitation and abuse didn't end with World War II.

For this cycle to end, the world needs to take a stand and declare once and for all that there are lines that cannot be crossed in war. These lines need to be backed up with war crime tribunals and aggressive monitoring. Systematic rape through forced prostitution is a crime against humanity that will only stop when it is given the importance it deserves.