In the course of the protracted armed conflict in Yemen, a six-day pause in fighting – called ‘days of tranquillity’ – enabled more than 306,000 people, including over
160,000 children under the age of 15, to be vaccinated in
a WHO–UNICEF campaign against cholera in October 2018.
5.1 What are they?
A variety of terms are used colloquially to refer to suspensions of hostilities, including pause, truce, armistice, days of tranquillity, windows of silence and ceasefire – at times prefaced with the adjective ‘humanitarian’. None of these terms is authoritatively defined, and they are often used interchangeably. All refer to temporary suspensions of active hostilities. The suspension of hostilities may be for a specific humanitarian purpose, or may be more general in nature.
The terminology may be confusing, but the different terms do not necessarily have different meanings. In 2018, for example, in the context of the conflict in Syria, the UN Security Council emphasized ‘the need for the parties to agree on humanitarian pauses, days of tranquillity, localized ceasefires and truces to allow humanitarian agencies safe and unhindered access to all affected areas’. There was no indication that these different terms were anything other than synonymous.
In situations where civilians are caught up in active fighting and a humanitarian response is severely hampered, a variety of actors frequently call for such measures. They have included, for example, the UN Security Council and General Assembly, regional bodies such as the EU’s European Council, human rights organizations, and sometimes the general public.
The objective of these calls is the same – a suspension of active fighting to limit the impact of the hostilities on civilians. But there can be a key difference in the purpose of the suspension: whether it is to allow a specific humanitarian activity to be conducted without risk of harm from the active fighting; or whether it is a generalized suspension of hostilities. While any cessation of hostilities is likely to alleviate the situation of civilians caught up in the fighting, generalized ceasefires aim to be a step towards negotiating the end of hostilities, rather than to facilitate specific humanitarian activities.
The details of ceasefires vary, but in the main suspensions of hostilities for specific humanitarian purposes are limited in scope, in terms of duration and location. Although they pause the fighting, this is usually a brief and localized interruption. The same is not the case for generalized ceasefires that are not related to specific humanitarian activities. These usually cover the entire geographic area of a particular conflict, and might not be time bound.
While any interruption in fighting can affect the conduct of military operations, the longer and more widespread it is geographically, the more significantly it can impair the pursuit and attainment of the strategic objectives of the hostilities. Pauses allow belligerents to conduct activities preparatory to the resumption of fighting, such as repositioning and resupplying forces.
This is one of the reasons why some states were unwilling to call for a generalized ceasefire in relation to the fighting in Gaza in 2023–24. Particularly in the early stages of the offensive, they were reluctant to interfere in Israel’s military campaign against Hamas and its right to use force to defend itself.
5.2 What does the law say?
IHL does not define any of the terms that are used to refer to temporary suspensions of active hostilities. Nor does it require parties to armed conflicts to adopt ceasefires or any such measures. In practice, however, a temporary cessation of hostilities can play a key role in giving effect to obligations under IHL, such as the evacuation of the wounded and sick, or allowing and facilitating the rapid and unimpeded passage of humanitarian relief consignments.
5.2.1 International armed conflicts
The Geneva Conventions and Additional Protocol I refer to such suspensions of hostilities only in relation to the removal of sick members of states’ armed forces from the battlefield. The First Geneva Convention provides, in Article 15, that: ‘Whenever circumstances permit, an armistice or suspension of fire shall be arranged, or local arrangements made, to permit the removal, exchange and transport of the wounded left on the battlefield.’
Two elements must be highlighted. First, IHL envisages that the conclusion of ceasefires is by agreement between belligerents. This reflects the reality that suspensions of hostilities can only really be protective if all the parties operating in a particular area agree to them. Second, IHL does not require such agreements to be concluded. But it strongly encourages belligerents to do so. The word ‘shall’ in Article 15 suggests an obligation to make a good-faith effort to reach agreement whenever circumstances objectively permit. Striving to reach agreement is not optional, there is a legal obligation to try to do so, subject to a wide margin of discretion depending on external circumstances – but not simply on the subjective preference of a party to the conflict.
A number of other provisions of IHL applicable in international armed conflicts refer to the possibility for belligerents to conclude ‘local arrangements’ for particular purposes, such as the removal of the wounded and sick, and particularly vulnerable civilians from besieged or encircled areas. What the arrangements should address is not specified, but a temporary cessation of hostilities would be an important element of any arrangement to allow the operations in questions.
Belligerents can conclude agreements on any issue they choose, even if not specifically referred to in IHL, so nothing prevents them from concluding agreements to temporarily suspend hostilities for other purposes, for example to allow and facilitate humanitarian relief operations.
5.2.2 Non-international armed conflicts
In relation to non-international armed conflicts, neither Common Article 3 of the Geneva Conventions nor Additional Protocol II specifically mentions ceasefires or other forms of suspension of hostilities. That said, Common Article 3(3) encourages parties to non-international armed conflicts to endeavour to bring into force, by means of special agreements, all or part of the other provisions of the Geneva Conventions. These special agreements could include temporary cessations of hostilities which, as previously noted, can play an important role in ensuring the protection afforded to civilians and the wounded and sick, and in facilitating humanitarian relief operations.
5.2.3 Interplay with other rules of IHL
Any humanitarian pauses that may be agreed do not affect protections and obligations under IHL. They are a way of giving effect to them.
For example, IHL requires that civilians and the wounded and sick who are moving in locations of active hostilities must be respected and protected. Belligerents must allow and facilitate the rapid and unimpeded passage of relief operations. These protections apply whether or not there is a ceasefire. But agreements to suspend hostilities to allow humanitarian movements reduce the risk that they may be caught up in the hostilities.
5.3 Operation in practice – challenges, good practice and recommendations
5.3.1 Reaching agreement
Like most other humanitarian arrangements discussed in this paper, to be truly protective, ceasefires must be concluded by agreement between all belligerents. Calls by the UN General Assembly and other actors, including the Security Council, are just that – an exhortation to the parties to the hostilities to stop the fighting for humanitarian purposes. It remains for the parties to reach agreement on the modalities.
Thus, when the UN Secretary-General made an appeal for a general ceasefire in March 2020 to assist efforts to fight against COVID-19 in conflict-ridden countries, that in itself did not achieve the necessary agreements on ceasefires. Nor did Security Council resolution 2532 (2020), which supported the Secretary-General’s appeal and called on ‘all parties to armed conflicts to engage immediately in a durable humanitarian pause for at least 90 consecutive days’ for humanitarian purposes, including for medical evacuations.
As with other humanitarian arrangements, intermediaries can play a central role to facilitate reaching agreement on ceasefires, and to maximize their effective implementation. Who is likely to play this role varies. If the principal purpose of the cessation of hostilities is to allow the passage of humanitarian relief, it may be the humanitarian actor who would conduct the operations in question. For example, the UN Emergency Relief Coordinator may facilitate agreements allowing the passage of a range of humanitarian organizations; the ICRC is likely to do so for its for its own operations.
Suspensions of hostilities are often one element of a package of measures to facilitate humanitarian response or evacuations, which also includes particular routes that can be used. The examples of negotiations of agreements given in chapters 3 (on evacuations) and 4 (on humanitarian corridors) of this paper also include undertakings to suspend hostilities.
Other actors can act as intermediaries. In 2017 in the Philippines, for example, the Moro Islamic Liberation Front, a separatist movement based on Mindanao island, facilitated the conclusion of a four-hour ceasefire between state armed forces and the Maute group, an Islamic State affiliate that was besieging the town of Marawi, to allow civilians to leave. In May 2023, the US and Saudi Arabia facilitated an agreement on a short-term ceasefire between the Sudanese Armed Forces (SAF) and the Rapid Support Forces (RSF).
5.3.2 Format of agreements to suspend hostilities
IHL does not specify the format that agreements to suspend hostilities should take. As in the case of the other arrangements discussed in this paper that require agreement between belligerents, a written agreement is preferable. This allows all elements to be accurately recorded and transmitted to those responsible for their implementation. The agreement could be in a single document accepted by both parties, or separate identical documents signed by parties individually through an intermediary.
Article 15 of the First Geneva Convention, which addresses ceasefires for the removal of the wounded and sick, refers to ‘armistices’, which are generally understood to be as more formal agreements, ‘suspension of fire’ and ‘local arrangements’. The latter might be concluded by commanders at field level, and be more limited in terms of duration and geographical scope.
Whatever the format, agreements to suspend hostilities are binding and must be implemented in good faith. What matters is that there is clarity about the location and duration of the suspension of hostilities and other relevant aspects that have been agreed.
5.3.3 What should agreements address?
Agreements should set out the precise details of the suspension of hostilities, including most notably:
- Where it will take place. Suspensions can be general or only apply in certain areas.
- When it will start and its duration.
- The types of activities that belligerents will refrain from conducting in the areas in question. Usually, they will be precluded from carrying out attacks and other offensive military operations. Agreements should specify whether other operations – such as laying of minefields, movement of troops, weapons and supplies, or building defensive lines – are permissible in the areas under a party’s control.
- What belligerents are required to do. They may be required to allow the movement of civilians, to facilitate the passage of humanitarian relief operations, and to allow repairs to essential infrastructure to be carried out. Precisely what is required depends on the purpose of the pause. For example, in the case of pauses to allow humanitarian relief to transit, in addition to routes and times, parties may agree which organizations are entitled to participate; and what arrangements, if any, must be put in place to ensure that only relief items are provided.
Belligerents should ensure that the details of the ceasefire agreements are communicated to their forces and to all relevant authorities, to ensure compliance by members of the armed forces and groups with the obligations that have been undertaken. Often, the suspension of hostilities only begins some days after the adoption of the agreement. Parties should use this time to instruct their forces on the measures they should take.
Similarly, details of the agreements should be communicated to civilians and to humanitarian organizations who are operating in the areas covered by the ceasefire, to allow them to make best use of it.
5.3.4 Monitoring
Arrangements to monitor the suspension of hostilities can be extremely helpful to ensure they are implemented as foreseen, and to defuse problems that may arise. However, it is often challenging to establish such arrangements: belligerents must agree to monitoring; and a party must be found who is willing and capable to meaningfully ‘monitor’ the suspension of hostilities.
While general ceasefires may include monitoring missions, agreements to suspend hostilities for a specific humanitarian purpose are much more dynamic in nature and must be implemented in shorter timeframes. Unless an international actor such as a peacekeeping force is already present and can be mandated to monitor implementation, it is unlikely that monitoring will be conducted on the ground.
Ceasefire agreements are bilateral agreements, and serious violation by one side can lead the other to suspend its own obligations and terminate the agreement. Such termination, even if preceded by warnings, would have dire consequences for those relying on the suspension of hostilities.
Even if the monitoring of belligerents’ conduct on the ground is not possible, the establishment of lines of communications with them and with the humanitarian actors operating during the suspension of hostilities are extremely valuable. Third-party arrangements to defuse any tensions between the parties may also be agreed upon; this is a role that could be played by the neutral intermediary who facilitated the conclusion of the agreement.
For example, in the case of Sudan, the May 2023 Agreement on a Short-Term Ceasefire and Humanitarian Arrangements established a Monitoring and Coordination Committee, consisting of representatives of the US and Saudi Arabia (the facilitators of the agreement) and of the parties to the agreement, the SAF and the RSF. The committee was tasked with maintaining regular contact with the two parties to coordinate the implementation of the ceasefire; and with receiving communications from humanitarian actors on behaviour that could undermine the ceasefire or the conduct of relief operations. It also served as a platform for mediating disputes between the parties.
5.3.5 Ceasefires to conduct specific activities
Usually, humanitarian ceasefires are concluded to allow life-saving humanitarian activities such as the evacuation of the wounded or the provision of goods essential to immediate survival, such as food, water, fuel and shelter materials.
In some instances, however, ceasefire arrangements are put in place for other, usually very specific purposes. These include the ‘days of tranquillity’. This mechanism has been used primarily by UNICEF, often in collaboration with WHO, to enable children to have access to healthcare during armed conflict. Frequently, days of tranquillity are agreed in order to undertake national immunization campaigns or other exclusively humanitarian activities. Like other suspensions of hostilities, days of tranquillity require the agreement of all relevant parties to refrain from impeding the movements and work of medical and other personnel during the designated days.
Another example was the ‘windows of silence’ facilitated by the OSCE Special Monitoring Mission (SMM) to Ukraine. As part of its mandate to contribute to reducing tensions in eastern Ukraine after 2014, the SMM facilitated and monitored the implementation of short-term localized cessations of hostilities to facilitate the maintenance and repair of critical infrastructure along the ‘contact line’. The windows contributed to the restoration of essential services for the civilian populations on both sides of the contact line, including water, electricity and gas supplies, and mobile communications.
The SMM obtained security guarantees from the Ukrainian armed forces and the armed groups, who would undertake to refrain from military operations at the specified locations and times to allow repair work to be conducted. The SMM deployed ‘mirror’ patrols – simultaneous, visible patrols on the two sides of the contact line, at times complemented by drones – to monitor adherence to the windows of silence. The SMM also acted as a liaison to facilitate re-establishment of the ceasefire in case of violations.
5.4 In conclusion
Calls for general ceasefires are understandable, because as long as hostilities persist, especially in densely populated areas, civilians will continue to suffer. However, since wider ceasefires can interfere with the strategic military objectives of one or both of the belligerents, they are more difficult to negotiate, more difficult to monitor, and more likely to be abused.
Temporary ceasefires for particular humanitarian purposes represent perhaps the most successful of the humanitarian arrangements discussed in this paper. The more limited their purpose(s), the more likely they are to be respected.
