Redesign and build the F-111 in Australia. Our techos know the current models inside out. Build a lot of them and train reservists to fly them. Fit them with anti-shipping cruise missiles and air to surface missiles. Maybe paint them with radar absorbing coatings for effect.
Forgeddabout the F-35. Stealth technology...sooo 20th century. Licence-build the latest Russian interceptors (we did a good job of licence- building the Avon Sabre and the Dassault Mirage III) Build a lot of them and train reservists to fly them.
Ground attack aircraft. Find the best and build lots of them under licence. Train reservists to fly them.
Licence-build the latest Russian supersonic anti-shipping cruise missiles that can knock a surface vessel to smithereens.
Big tanks??? Having a few is OK for the macho, but maybe better to have lots of the best anti-tank and anti surface vehicle weaponry. Lots of fast APCs and light tanks. Solar-powered would be nice.
Lots of big surface vessels? Look at what the Argentinians did to the Royal Navy with a few Exocets and Skyhawks. Worth a read on Wikipedia. We need lots of smaller surface vessels that are capable of defending themselves with weapons other than pop-guns.
