Despite complaints from some Japanese businesses and diplomats, the Japanese government remained in basic agreement with United States policy toward China and Indochina. The government held back from large-scale aid efforts until conditions in China and Indochina were seen as more compatible with Japanese and United States interests. Of course, there also were instances of limited Japanese cooperation. Japan's response to the United States decision to help to protect tankers in the Persian Gulf during the Iran–Iraq War (1980–88) was subject to mixed reviews. Some United States officials stressed the positive, noting that Japan was unable to send military forces because of constitutional reasons but compensated by supporting the construction of a navigation system in the Persian Gulf, providing greater host nation support for United States forces in Japan, and providing loans to Oman and Jordan. Japan's refusal to join even in a mine-sweeping effort in the Persian Gulf was an indication to some United States officials of Tokyo's unwillingness to cooperate with the United States in areas of sensitivity to Japanese leaders at home or abroad.