she continued under the direct operational control of cincaf into the 1930s, being later reassigned to the south china patrol and observing conditions along the south china coast during the period following the outbreak of the undeclared sino-japanese war in july 1937. as tensions increased in the orient in 1940 and 1941, admiral thomas c. hart, cincaf, incrementally reduced the asiatic fleet's presence in chinese waters. withdrawn to the philippines in may 1941, "tulsa" joined the inshore patrol, guarding the sea approaches to manila bay.