Purchase: buy a vehicle outright or contract a private corporation to provide that service on demand. The vehicle does not have to be operational by 2030, as long as the contract is signed this will resolve YES.

Suborbital is here understood to include fractional orbit systems

The vehicle (or its upper stage) should be capable, at the very least, of travelling between anywhere in the US and Japan.

Obviously, the vehicle must have a payload capacity. However, I will not presuppose to judge what this might be. If the US military signs a contract within the spirit of this market that will be enough.

The capability should outcompete existing cargo planes. That means that it needs to maintained in such a way that it can be utilised in under 12 hours from first notice.