The subs may deter some attacks from underwater if they employ a more defensive role but that will not be a major threat in any major conflict. The way I see it is that this is just bringing the US, Britain and Australia closer which is probably not a great thing, in that we will be asked to help more than we will be asking for help.
The threat in any future war will be from unmanned drones and other non-conventional weapons like EMPs and cyberattacks. This is where we should be investing more of our dollars as we do not have the personnel or large scale military equipment to defend our borders.
Australia has one of the best up and coming defence contractors in EOS. These guys are doing wonderful things with laser weapons (as I understand they can clear space debris with these lasers which means they can destroy satellites), great things with drones, counter drones and other lethal tech. Give these blokes $1t over 5 years and we will be a huge force.
We also have alot of nerds, who can do great things with computers. We just need to attract the right people or wrong people (who are usually better suited for the right job) with a few CIA recruitment procedures and start developing hacking software to disrupt the ability for of warships and carriers to communicate with satellites.
