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ICE Case Studies
Number 320
by Jim Lee

Timor-Leste and Australia Undersea Border Dispute

I. Case Background
II. Environment Aspect
III. Conflict Aspect
IV. Env. - Conflict Overlap
V. Related Information


1. Abstract

Timor and Australia share an ocean boundary through an overlap in the maritime jurisdictions. This includes disputes over sea resources but also resources from the sea bed. This unfinished dispute pre-dates the state of Timor and dates back to Indonesian rule. Before then, the Portuguese ruled Indonesia, but the issue of a maritime boundary with Australia was of little importance then. As it turns out, this area is of great importance with significant energy resources. A 2017 agreement finalized the treaty, though with some final twists and turns.

2. Description

It is likely that the original Australians travelled on the seas from Timor. The Timor Sea is rather shallow now and 40,000 years ago it was much lower in elevation. In 2002 Timor gained indepedence. It then proceeded to negotiate with Australia on recognition of EEZ and ECS borders. Timor argue that a midway point should embark both the above and undersea boundaries. Australia wanted to differentiate the two, maintaining that the sea resources are measured at the sea surface should use the mid-point, while the underseas resource lines the limits of the continental shelf.

A 2006 treaty set a temporary maritime border in the Timor Sea. The understanding set a 50-year timeframe for negotiations absent a permanent agreement. In January 2017, Timor annulled the understanding, charging that Australia has spied on them during the negotiations, thus tainting the outcome.

Australia's position is that its maritime border should extend beyond its continental shelf. There are several layers to the story. The border was originally negotiated with Indonesia in 1972. At the time Timor was governed by Portugal but who decided to be part of the negotiations or ultimate treaty. At the time, they wanted to wait until the UN Law of the Sea negotiations were concluded. Thus, the border area contained an undefined protion known as the "Timor Gap". Indonesia forcibly took Timor in 1975 so this gap needed to negotiated by a new understanding.

3. Duration: 1975-2017

4. Location

Continent: Asia
Region: Southeast Asia
Country: Timor

5. Actors:

Timor-Leste and Australia

"The Permanent Court of Arbitration in The Hague today announced the parties reached an agreement on Wednesday over the disputed territory, which contains large oil and gas deposits worth an estimated $40 billion." (Norman, 2017).


6. Type of Environmental Problem: Border

Australia has already heavily developed oil and gas resources on their side of the Timor Sea. Petroleum resource were found in the Timor Sea in the 1970s.

Australian Department of Foreign Affairs and Trade

7. Type of Habitat: Ocean

8. Act and Harm Sites: Timor-Leste and Australia

There was a major oil spil in the Timor Sea in 2009 (Burrell).


9. Type of Conflict: War

No conflict is expected but the Australian Secret Intelligence Service (ASIS) planted listening devices during negotiations over the Greater Sunrise oil and gasfields. This led to a halt to the negotiations on the part of Timor.

10. Level of Conflict: Threat

11. Fatality Level of Dispute (military and civilian fatalities): 0


12. Environment-Conflict Link and Dynamics: Direct

The Greater Sunrise fields, the area under contention in the Timor Gap, were found in 1974. ETAN puts the value of the resources in the tens of billions of dollars. Tony Clifton observes that Timor, a coungry with virtually known resources, has already become dependent on the flow of income from the energy sources.

13. Level of Strategic Interest: Bilateral

A 1972 treaty with Indonesia, of which Timor was a part, set the border point. This was a time when countries were extending the Exclusive Economic Zones (EEZs) to 200 miles. The border is not set at the geographic midway point between the two countries. Rather, it is set through Extended Continental Shelf (ECS) claims by Australia. Such means for demarcation are well-recognized. By this measure, the boundary was the Timor Trench. Timor, after achieving independence from Indonesia claimed this arrangement was unfair (Greenville).

"Sunrise Energy Field", Corgan Energy Group

14. Outcome of Dispute: Complete

The Timor Sea Treaty between East Timor and Australia was signed on May 20, 2002. It lid out a basic framework for the development of offshore sea resources in a jointly-shared seabed. The day was important for East Timor, since it is also the day when East Timor became independent and shed United Nations rule. The follow-up Treaty on Certain Maritime Arrangements in the Timor Sea (CMATS) in 2007 extended the treaty terems out 50 years -- to 2057. Australia allowed a concession to Timor that allowed 90 percent of the income in the Joint Development Area to Timor (King, Grenville).


15. Related ICE Cases

South China Sea
Talpatti Island
Turkey-Greece Sea Dispute
Beaufort Sea Dispute
Italy and Switzerland Alpine Border

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16. Relevant Websites and Literature

Andrew Burrell (29 April 2011). "Montara oil spill firm seeks permission for more drills". The Australian News. >br> East Timor and Indonesia Action Network (ETAN).
Jane Norman, "Australia and Timor-Leste strike deal to end maritime boundary dispute", ABC News,
Accessed September 2, 2017.

Henry Belot and Emily Stewart, "East Timor tears up oil and gas treaty with Australia after Hague dispute", ABC News,

Stephen Grenville, "East Timor, Australia and the 'Timor Gap'", The Interpreter, November, 2017

Robert J. King, “The Timor Gap, 1972-2017”, March 2017. Submission No.27 to the inquiry by the Australian Parliament Joint Standing Committee on Treaties into Certain Maritime Arrangements - Timor-Leste. p.48.

Tony Clifton, "The battle for the Timor Sea, home of oil, gas, hot air and hope", The Monthly

Agreements, Treaties, and Negotiated Settlements Projet (ATNS), "1972 Seabed Boundaries Agreement between the Commonwealth of Australia and the Republic of Indonesia on Seabed Boundaries in the Area of the Timor and Arafura Seas.",