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ITER Agreement Signed (2006)

The signing of the ITER Agreement by seven parties representing half the world’s population — creating the legal framework for the most ambitious international science project in history.

Reviewed Last reviewed: 9 Aug 2026 · Category: History & Milestones

The Agreement

On November 21, 2006, representatives of the European Union, Japan, the United States, Russia, China, South Korea, and India signed the ITER Agreement in Paris, establishing the ITER Organization and committing to jointly construct and operate the world’s largest fusion experiment. The seven parties represent over half the world’s population and ~85% of global GDP.[1]

Unique governance: ITER uses a unique “in-kind” contribution model: each member manufactures specific components in their domestic industries, which are then shipped to Cadarache for assembly. The EU provides ~45% of construction value as the host party; the remaining six members each provide ~9%. This model distributes technological expertise but creates enormous coordination complexity.

Path to the Agreement

ITER’s origins date to the 1985 Reagan-Gorbachev summit. The original conceptual design was completed in 1990, followed by the engineering design (1992–2001). The U.S. withdrew from ITER in 1998 (budget concerns) but rejoined in 2003. Site selection between Cadarache (France) and Rokkasho (Japan) was resolved in 2005 through a diplomatic package that gave Japan the broader approach programme, including JT-60SA.[2]

Significance

The ITER Agreement represents the largest international scientific collaboration outside of the International Space Station. It created a binding framework for a project expected to operate until at least the 2050s, spanning multiple generations of scientists and political administrations.[3]

Sources

  1. ITER Organization. "ITER Agreement." iter.org.
  2. Clery, D. A Piece of the Sun: The Quest for Fusion Energy. Overlook Press, 2013.
  3. Ikeda, K. "ITER on the road to fusion energy." Nuclear Fusion, 50, 014002, 2010.

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