Treaties are agreements entered into between States, either bilaterally or multilaterally. The Commonwealth, and not the States, is Australia’s international representative. It is within executive power to negotiate and execute such treaties but international treaties are not self-executing, requiring incorporation by legislation into domestic law (Encyclopaedic Australian Legal Dictionary).
Most treaties do not come into force when signed. They have a clause which specifies the requirements of the treaty entering into force. The clause may include a ratification date and a requirement that a certain number of parties have ratified before it can become law.
If you are searching for a multilateral treaty, a database such as the Flare Index to Treaties, which contains the most significant treaties from 1856 to the present, is a good place to start. This will help you identify the name of the treaty and provide a link to the text of the treaty. To find the current status information, you will then need to access the site where the material is lodged or deposited, such as the United Nations Treaty Collection.
The Australian Treaty Database (DFAT) and the Australian Treaties Library (AustLII), which contains the Australian Treaty Series, are good resources when looking for Australian treaties. These resources contains all multilateral and bilateral treaties to which Australia is a signatory.
Hein Online Treaties and Agreements Library has United States treaties and the WorldLII International Treaties Collection is a good starting point to locate a range of treaties from other jurisdictions such as the United Kingdom, Canada and New Zealand.
The Vienna Convention on the Law of Treaties is the UN agreement that governs the law relating to treaties.
The 1648 Peace Treaties of Westphalia established the framework for modern treaties and recognised the right of the sovereign to govern free from outside interference. By the 20th century, the subject matter of treaties has been greatly expanded and treaties have become the principal source of Public International Law. Treaties can also include the creation of rights for individuals.
The treaty text may provide for the manner by which it takes effect. Generally, treaties will enter into force when it has been signed and ratified by a certain number of parties. Parties to a treaty may ratify a treaty with reservations or other declarations unless the terms of the treaty place restrictions on those actions. A reservation is a country's attempt to modify certain terms of the treaty, as it applies between itself and other countries.
Multilateral treaties are published in sets such as the United Nations Treaty Series (UNTS). Only treaties deposited with the UN Secretary General become part of the UNTS. Although most multilateral (and many bilateral) treaties are deposited with the UN as a matter of course, states are under no specific obligation to do so. A good source of information on the role of the UN as a treaty depository is the Summary of Practice of the Secretary-General as Depository of Multilateral Treaties on the UN website.