Thousands of soldiers from the United States, Indonesia, Australia and other allied forces demonstrated their armor capabilities on Sunday in combat drills on the Indonesian island of Java at a time of increased Chinese aggression in the region. President Joe Biden's administration has been strengthening an arc of military alliances in the Indo-Pacific to reassure allies alarmed by Beijing’s increasingly provocative actions in the disputed South China Sea, which has become a battleground for U.S-Chinese rivalries. During the drills, Australian forces deployed five M1A1 Abrams battle tanks and the Indonesian military, deployed two Leopard-2 tanks for the two-week combat exercises in Banyuwangi, a coastal district in East Java province which began Sept. 1.