A Maritime Exclusion Zone (MEZ) is a military exclusion zone at sea. While it is an accepted concept internationally, it is not the subject of an explicit

treaty A treaty is a formal, legally binding written agreement between sovereign states and/or international organizations that is governed by international law. A treaty may also be known as an international agreement, protocol, covenant, convention ...

, and there has been variation in naming including: "naval exclusion zone", "maritime security zone", "blockade zone", "maritime operational zone", "area subject to long distance blockade" and "area dangerous to shipping". During armed conflicts since the

Russo-Japanese War The Russo-Japanese War (8 February 1904 – 5 September 1905) was fought between the Russian Empire and the Empire of Japan over rival imperial ambitions in Manchuria and the Korean Empire. The major land battles of the war were fought on the ...

in 1904, belligerents have sometimes established maritime zones to control or prohibit access of foreign ships and aircraft, with varying levels of restriction and risk of attack on merchant vessels. A MEZ is different to a

blockade A blockade is the act of actively preventing a country or region from receiving or sending out food, supplies, weapons, or communications, and sometimes people, by military force. A blockade differs from an embargo or sanction, which are ...

in that enforcing naval forces are not deployed close in to a port but over an extended area, and that offending vessels are generally subject to attack rather than confiscation. The development of the MEZ concept from a blockade reflects the technological changes enabling longer ranges for detection systems and weapons.

The modern concept

A more modern and consistent approach has been adopted since the San Remo Manual on International Law Applicable to Armed Conflicts at Sea was published in 1994, which defined blockade zones in articles 105 to 108. MEZs warn vessels and aircraft to avoid the area, to reduce the risk that neutral or non-combatant vessels will be mistakenly targeted. However merchant ships, neutral or enemy, do not automatically become a lawful target by being in a MEZ; they must be evaluated as legitimate military objectives before being targeted. Many military Law of Sea manuals, including those of the Australian, Canadian, German and United Kingdom navies, set out regulations for the operation of MEZs, based on the internationally legally recognized San Remo Manual. The Australian manual notes that "there is no specific international law treaty provision referring to aritime Exclusion Zones however, their use has acquired a degree of validity under

customary international law Customary international law consists of international legal obligations arising from established or usual international practices, which are less formal customary expectations of behavior often unwritten as opposed to formal written treaties or c ...

". Neutral vessels must be given safe passage through a MEZ if it significantly impedes safe access to neutral ports, although they may be searched in transit by a belligerent. Sometimes a "blue safe maritime corridor" through a MEZ is defined and published to regulate such safe access. MEZs have been routinely employed, for example by the United Kingdom and Argentina during the

Falklands War The Falklands War () was a ten-week undeclared war between Argentina and the United Kingdom in 1982 over two British Overseas Territories, British dependent territories in the South Atlantic: the Falkland Islands and Falkland Islands Dependenci ...

, by Iran and Iraq during the Tanker War, by the United States during the

Gulf War , combatant2 = , commander1 = , commander2 = , strength1 = Over 950,000 soldiers3,113 tanks1,800 aircraft2,200 artillery systems , page = https://www.govinfo.gov/content/pkg/GAOREPORTS-PEMD-96- ...

and

Iraq War The Iraq War (), also referred to as the Second Gulf War, was a prolonged conflict in Iraq lasting from 2003 to 2011. It began with 2003 invasion of Iraq, the invasion by a Multi-National Force – Iraq, United States-led coalition, which ...

, and by Russia in the

Russian invasion of Ukraine On 24 February 2022, , starting the largest and deadliest war in Europe since World War II, in a major escalation of the Russo-Ukrainian War, conflict between the two countries which began in 2014. The fighting has caused hundreds of thou ...

. MEZs are not required in the immediate area of naval operations for a belligerent to control an area "within which hostilities are taking place or belligerent forces are actually operating", where the activities and communications of neutral vessels and aircraft may be prohibited.

References

Blockades Law of the sea Exclusion zones {{mil-stub

The modern concept

See also

References