Treaties — Validity — Alleged illegality of USSR-USA Treaty on Limitation of Strategic Offensive Weapons, 1979 (salt II Treaty) — Plaintiff claiming Australia in breach of international law by its continuing support of the Treaty — Whether salt II Treaty in conflict with the provisions of the Treaty on Non-Proliferation of Nuclear Weapons, 1968 (Nuclear Non-Proliferation Treaty) — Whether provisions of salt II Treaty enhancing the danger of nuclear war — Whether plaintiff having special interest — Whether plaintiff’s interest shared with public at large — The law of Australia