Island Nations Brace for Rising Seas: Legal, Maritime and Digital Strategies to Preserve Statehood

International law defines a state by four criteria: a defined territory, a permanent population, an effective government and the capacity to engage with other states. For Tuvalu, Kiribati and the Marshall Islands—each only about two metres above today’s sea level—projected rises of at least 0.5 metres and possibly up to two metres by 2100 threaten to erase their land. While existing treaties do not spell out how statehood survives such loss, the Pacific Islands Forum and the Alliance of Small Island States have repeatedly affirmed the need to protect nationality, culture and self‑determination even if physical territory disappears.

Under the United Nations Convention on the Law of the Sea, maritime zones are measured from baselines drawn along the low‑water line. Rising oceans could push coastlines inland, forcing baselines to move and potentially shrinking exclusive economic zones that provide vital fisheries and other marine resources. In response, affected states have urged that established baselines and outer limits remain fixed, preserving legal certainty. The International Law Commission and the International Court of Justice have clarified that UNCLOS does not require states to redraw baselines once they have been lawfully set, reinforcing calls for stability.

Tuvalu is spending millions of dollars on a coastal adaptation project while also developing a “digital nation” model that moves government functions, civil registration and cultural archives into a virtual environment. The initiative includes three‑dimensional scans of its islands and a digital identity system to keep diaspora communities linked to public life. In 2023 the Falepili Union Treaty with Australia formally recognised Tuvalu’s continued statehood and created a special visa pathway, allocating 280 visas for its citizens. According to the 2026 UN report, 90 percent of Tuvalu’s population applied for the first round of those visas in the previous year, illustrating the scale of mobility planning to avoid statelessness.