Following its success with the UH-72 Lakota, Airbus US successfully bid the Tiger as a replacement for the cancelled AH-70 Arapaho.
Entering service with the US army and demonstrating significantly improved performance over the AH-1Z the USMC evaluated the type against the Viper and determined that Tiger would be procured instead of new build AH-1Zs. While this led to a situation of the USMC operating a mixed fleet of rebuilt AH-1Ws and Tigers, the impact was not as great as feared as the USMC version had a very high level of commonality with the US Army version, delivering significant economies of scale.
Interestingly Australia's development, integration and certification of Hellfire and other key US systems on Tiger led to significant royalties together with coproduction options for Australia. Tiger also entered in a spiral development program for the US, which Australia became a full partner in, eventually leveraging additional airframes, local assembly and becoming a key strategic supplier to the US fleet.