An Achilles' heel of the Indian nuclear power programme, however, is the fact that India is not a signatory of the Nuclear Non-Proliferation Treaty. This has many times in its history prevented it from obtaining nuclear technology vital to expanding its nuclear industry. Another consequence of this is that much of its programme has been domestically developed much like its nuclear weapons programme. The United States-India Peaceful Atomic Energy Cooperation Act seems to be a way to get access to advanced nuclear technologies for India.