What would make Hawaii a credible deterrent base?

Would a public crash program to turn Hawaii into the major Pacific base have been a better deterrent?

Potentially, but only if the United States backed the announcement with the supplies, infrastructure, and support needed to sustain the fleet.

A large, public base-building program in Hawaii could have sent a more credible signal than an unsupported fleet deployment. The essential condition was sustained investment rather than an announcement alone. At times, wartime Britain found more resources for Singapore than the still-neutral United States devoted to Hawaii. Embargoes and diplomatic pressure on Japan advanced faster than the logistics and infrastructure needed to protect the forward fleet enforcing that policy.