Japan’s new security laws took effect Tuesday, enabling its troops to fight overseas for the first time since World War II. The laws largely expand the role of the Self-Defense Forces overseas.

The country is now allowed to exercise the right to collective self-defense, or coming to the aid of the United States and other nations under armed attack, even if Japan itself is not. But the law remains controversial among members of the public, who fear it could erode Japan’s post-war pacifism. Hundreds of people, including high school students, joined protests across the country over the weekend.

A survey conducted by Japan’s Kyodo news agency indicates nearly half of the population voted “No” for the change.