Fears of a third world war spiked over the weekend as Japan activated their marines for the first time since World War 2. About 2,100 members of the Amphibious Rapid Deployment Brigade (ARDB) were activated in a ceremony in which the troops wore camouflage.

ARDB also completed a 20-minute mock drill for the public in which the “retook” an island from an invading force. According to Reuters, the formation of the Japanese marine brigade is controversial because amphibious units can project military force and could, critics warn, be used to threaten Japan’s neighbors. In its post-WW2 constitution, Japan renounced the right to wage war.

The newly activated unit is highly trained to counter invaders occupying Japanese islands along the edge of the East China Sea that Tokyo fears are vulnerable to attack by China. “Given the increasingly difficult defense and security situation surrounding Japan, defense of our islands has become a critical mandate,” Tomohiro Yamamoto, vice defense minister, said in a speech.

The brigade is the latest component of a growing marine force that includes helicopter carriers, amphibious ships, Osprey tilt-rotor troop carriers, and amphibious assault vehicles. All of these marine measures are meant to deter China as it pushes for easier access to the Western Pacific.

The activation of the 2,100 strong ARDB takes Japan a step closer to creating a force similar to a U.S. Marine Expeditionary Unit (MEU) able to plan and execute operations at sea far from its home base. “They’ve already demonstrated the ability to put together an ad hoc MEU. But to have a solid, standing MEU capability requires a concerted effort,” Grant Newsham, a research fellow at the Japan Forum for Strategic Studies. “If Japan put its mind to it, within a year or year and a half it could have a reasonable capability.”

Coincidentally, the United States last month deployed its F-35Bs for their first at-sea operations aboard the USS Wasp amphibious assault ship, which is based in Sasebo. The Kyushu port is also home to Japan’s Ise and close to the ARDB’s base.

All of these military decisions seem to coalesce and reignite fears of a war. The amphibious marine force of Japan has been advancing over the past few years with the help of the United States Marines.