The Australian government has proposed tougher restrictions on former defence military personnel who want to train foreign militaries as the nation prepares to share nuclear secrets with the United States and Britain. Defence Minister Richard Marles introduced legislation into the Parliament on Thursday aimed at safeguarding military secrets. Last year, he ordered the Defence Department to review standards after reports that China had approached former Australian military personnel to become trainers. Australia's allies the United States, Britain and Canada share concerns that China is attempting to poach Western military expertise. The review recommended strengthening of already-robust legislation as Australia deepens…