There's renewed concern about China's construction of a fleet of commercial ferries that could be used in any attack on Taiwan.

The RoRo ferries could be used to land tanks, equipment and personnel without needing a port.

According to an ABC report published today,  a classified Pentagon report from earlier this year describes the build-up of the fleet as rapid.

• Guest: Sam Rogeveen, Director of International Security at The Lowy Institute
• Producer:  Brooke Young