Behavioral psychologists know that denial about norm violation is pervasive, and can even be functional for individuals though not for organizations.  Individuals may not be aware of their dishonesties and often ignore those of family, friends, and co-workers because the cost of confrontation is large and the benefit small.  Co-workers may challenge norm violations by weaker colleagues but rarely by powerful superiors.  Punishment for norm violation is often employed to reinforce organizational hierarchy rather than to enforce uniform standards of behavior.  Something similar explains the reluctance of states to address violations of the non-annexation norm, the prohibition against territorial aggrandizement believed to undergird the post-Second World War international order.  Chapter 1, Article 2, Section 4 of the United Nations (UN) Charter expresses the norm in unequivocal language: “All Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state…”  States are inconsistent in their objections of violations of the norm and, unless their territory is the target, rarely use armed force to oppose or reverse them.  As the following survey shows, annexations are often successful and the success of any particular annexation reflects the relative military might and diplomatic influence of the annexing state.

The extraordinary transfers of territory between the end of the Second World War and the adoption of the UN Charter in 1949, including both territorial restorations and novel impositions of territorial sovereignty, were and are treated as fait accompli by the international community.  The Soviet Union redrew the boundaries of Eastern Europe, annexing eastern Poland to itself while annexing eastern Germany to Poland. Greece received the Dodecanese Islands.  Manchuria and Taiwan together with the remaining continental concessions were restored to China.  UN Trusts over Italian Somaliland and Libya were assumed by Britain while Ethiopia annexed Eritrea.  UN Trusts over the Marshall Islands, Micronesia, Northern Mariana Islands and Palau were assumed by the United States.

Three annexations occurring soon after decolonization – Tibet by the People’s Republic of China (PRC) in 1949; Portuguese Goa by India in 1961; and Dutch West Papua by Indonesia in 1963 – are today also treated as fait accompli.  The international community largely acquiesced because the annexing states were new regional powers whose leaders and populations were inspired by passionate anti-colonialism, because anti-imperialism was embraced at least rhetorically even by the major powers, and because the annexed territories were deemed either too remote or too insignificant by major powers to justify interstate war.

A fourth annexation in the same time period merits mention.  The partition of Kashmir between India and Pakistan at independence in 1947 resulted in three interstate wars.    In the 1950s the PRC undertook a stealth annexation by road construction of Aksai Chin in northern Indian Kashmir, a casus belli for the 1962 Sino-Indian War.  Although the international community has attempted to mediate the conflicts over Kashmir, it has not been unwilling to impose resolutions by armed force.

Five subsequent territorial annexations – Aouzou Strip in Chad by Libya in 1972, Portuguese East Timor by Indonesia in 1975, Khuzistan in Iran by Iraq in 1980, the Falkland Islands by Argentina in 1982, and Kuwait by Iraq in 1990 – were unsuccessful.  Following a protracted civil war, Chadian forces supported by the United States and France expelled the Libyan army.  Insurgency and international condemnation led by Australia and the Vatican persuaded Indonesia to withdraw from Timor-Leste without an interstate war.  The invasion of Iran by Iraq resulted in a protracted interstate war that Iraq lost.  Britain defeated Argentina in a brief war.  Iraq relinquished Kuwait in an interstate war by a less than universal coalition of states led by the United States.  Rather than the strength of the anti-annexation norm, the failure of these five annexations is attributable to the relative military weakness and diplomatic isolation of the annexing states.

Eight more annexations were successful though each was and continues to be criticized by some states.  Western Sahara was annexed by Morocco in 1976.  Turkey annexed northeastern Cyprus in 1983 when it established the Turkish Republic of North Cyprus, a statelet that only it recognizes.  Israel annexed East Jerusalem in 1980, Golan Heights in 1981, and is now slowly annexing parts of the West Bank.  Russia occupied Georgia’s Abkhazia and South Ossetia in 2010, effectively annexing both after signing treaties with the statelets established in 2014 and 2015.  Also in 2014, Russia annexed Crimea and effectively annexed Donetsk by supporting the separatist Donestsk People’s Republic.  What these eight cases have in common is that the annexing state is militarily powerful and diplomatically influential.  North Atlantic Treaty Organization (NATO) member state Turkey possesses a large army with recent combat experience in Syria, Iraq and Libya.  Morocco is a Major Non-NATO Ally (MNNA) of the United States.  Israel is also an MNNA and one of only nine nuclear weapons states.  Russia has a large military with recent combat experience in Syria, Libya and Ukraine and the largest nuclear weapons arsenal on the planet.  Attributable to the military might and diplomatic influence of the annexing states, the success of these annexations underscores the weakness of the norm.

Of the 17 cases of annexation of terrestrial territory since the UN Charter was adopted, 12 appear successful.  Four more cases involving maritime or extraterrestrial territory reinforce the lesson that the non-annexation norm is weak.

Although little remembered today, the negotiation of the 1982 UN Convention on the Law of the Sea (UNCLOS) was prompted in part by Iceland’s unilateral assertion of authority over its national waters beyond the traditional limit of three nautical miles.  That led to the Cod Wars, a non-armed conflict with Britain between 1958 and 1975.  Iceland ultimately prevailed, with the important consequence that UNCLOS permits coastal states to extend authority over their national waters 200 nautical miles from their shores as an Exclusive Economic Zone (EEZ).  States with extensive coastlines were the obvious beneficiaries.  States with numerous small island possessions, Britain and France in particular, were the less obvious beneficiaries.

With its EEZ areas often overlapped by those of neighboring East Asian and Southeast Asian states and no distant island possessions, the PRC is particularly disadvantaged compared with every other major power under UNCLOS.  In response to that inequity, Beijing has claimed nearly all of the South China Sea as its national waters.  To make the claim more concrete the PRC engaged in massive maritime reclamation on the islands and reefs of the Spratly Islands.  The United States together with most of the states in Southeast Asia dispute its claim.  In 2019 Turkey claimed a large stretch of the most the Eastern Mediterranean as its EEZ, ignoring sovereignty of Cyprus and of Greece over Crete and Rhodes.  Like Iceland, the PRC and Turkey may prevail through persistence.

Article II of the 1967 Outer Space Treaty incorporates the non-annexation norm in the following language: “Outer space, including the moon and other celestial bodies, is not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means.”  However, in 2020 the United States, Britain, Japan, Australia, Canada, Italy, the United Arab Emirates and Luxembourg negotiated the Artemis Accords, an agreement to establish an international legal basis for the development of resources on the Moon, Mars and beyond.  Russia and the PRC were unsurprisingly unimpressed, suspecting that it threatened future annexation of territory on the Moon using a condominium dominated by the United States.

The weakness of the non-annexation norm is evident in the inconsistency with which the most powerful states treat violations: they justify their own, endorse or ignore those by their allies, and denounce those by their rivals.  The United States claimed the Artemis Accords are consistent with the 1967 Outer Space Treaty, endorsed Morocco’s annexation of Western Sahara, ignored Israel’s annexation of parts of the West Bank, denounced Russian annexation of Crimea, and reacted to the Chinese annexation of the South China Sea with ‘freedom of navigation’ exercises in which U.S. Navy vessels sail through the disputed waters with the support of some though not all of its allies.  Russia defiantly annexed Crimea, criticized Israeli annexation of parts of the West Bank, criticized the Artemis Accords, and maintains neutrality on Chinese annexation of the South China Sea.  The PRC insists that its annexation of the South China Sea is the assertion of control over its historic waters, withheld criticism of the Russian annexation of Crimea, strongly criticized Israeli annexation of parts of the West Bank, and criticized the Artemis Accords.

Against the speculation that a hypothetical world without the non-annexation norm would present more cases of territorial aggrandizement, the available evidence shown here that 12 of 17 real world cases appear successful or potentially so, and that their success reflects the relative power of the annexing state, suggests otherwise.  With or without the norm, powerful states are willing to accept the risks of claiming territory from their weaker neighbors or the global commons.