Clearly, these are not isolated incidents.

The terrible reality is that one in three women will experience violence in their lives. Of those affected, an alarming but uncounted number of women are specifically targeted because they are engaged in public life. It is a pervasive but often overlooked barrier that prevents women across the world from having their voices heard. On International Women’s Day, we must call attention to this problem.

Through the decades, female leaders have been pushed down, shoved aside and beaten up. Too many still suffer from harassment, intimidation and violence simply for being female and politically active. These horrific acts — whether directed at women running for office or those simply lining up to vote — are intentional efforts to demean and restrict the political participation of an entire gender. There are often no consequences for the aggressors in these cases. We are frequently told that such violence is cultural, but I say it is criminal and we have to stop it.

Of course, attacking anyone — male or female — for political reasons is abhorrent. But eliminating gender-based persecution is important because women in government can be counted on to raise issues that others overlook, to support ideas that others oppose, and to seek an end to abuses that others accept. And perhaps because of their growing ranks in politics, women across the world have experienced a backlash in person and online. We cannot allow violence to be the cost for women who are simply exercising their fundamental human and political rights.

While the threat of violence is far from the only barrier for women in politics, it has a deep and long-term impact. Because harassment and violence often occur in private and protected spaces, many have learned not to complain about it. If they speak up, they run the risk of appearing to be a liability, rather than an asset to party leaders. Even worse, they can sometimes subject themselves to further harassment and discrimination. In a vicious cycle, such attacks, especially on high-profile women, dampen the political aspirations of other women and girls.

Activists and leaders around the world are beginning to recognize the scale of the problem and are taking steps to address it. A few countries have introduced legislation to criminalize acts of violence against women in politics. Bolivia, for instance, finally passed a law to protect female politicians after 12 years of grass-roots activism and the killings of Quispe and Rivera.

Passage of such laws is an important step, although we must advocate for their effective and consistent enforcement. Legislation, however, is not the solution everywhere: We need to bring other strategies to bear.

To that end, the National Democratic Institute will launch a global call to action next week to stop violence against women in politics. As the chairwoman of the institute’s board, I will be convening a meeting to launch this initiative alongside the U.N. Commission on the Status of Women. It will recommend concrete actions that international and individual actors can take, many of which are basic but common sense.

For example, the United Nations does not currently have specific reporting on acts of violence against women who engage in politics. The U.N. Special Rapporteur on Violence Against Women and Girls should start including this kind of violence in its investigations.

Because I believe in democracy, I believe that each person should be able to go as far as her or his talents will allow. Women and girls around the world who share that belief are ready to shape the future of their countries. Integrity, dedication to public service, and hard work should be the only entry fee to politics.

I have often said that success without democracy is improbable, and democracy without women is impossible. If we fail to act on behalf of the current and future female leaders in our world, the cost to our democracies will be too high.

When a woman participates in politics, she should be putting her hopes and dreams for the future on the line, not her dignity and not her life. It is time to put an end to the scourge of violence against women in politics, and to ensure that what happened in Uganda, Bolivia and elsewhere around the world does not stop women from being heard and making change.