Next along the spectrum are measures – threatened or applied – to pressure one or all of the conflict parties to modify their behaviour or position. They work by raising the costs of intransigence, comprising an array of formal sanctions as well as other forms of condemnation and pressure, including legal and diplomatic sanctions as well as other largely symbolic protests or penalties.
Formal sanctions are one of the principal instruments available to the international community to enforce international law, norms and standards. Imposing such measures is typically high on the agenda of international responses to conflict, often with the goal of getting their targets to cease unacceptable behaviour, rather than to encourage them to negotiate a settlement per se. Usually enacted by the body of an international organisation (such as the UN Security Council), they are occasionally undertaken by a group of states or unilaterally by one influential state or group (such as the US or EU). Some sanctions may originate in international civil society activism, such as sports or cultural boycotts like those enacted against apartheid South Africa and threatened against China more recently.
Usage has evolved quickly since the 'sanctions boom' of the 1990s. UN sanctions targeting war economy commodities (such as diamonds, oil or timber) have aimed at inhibiting war-making capabilities. Targeted or 'smart' sanctions aim to minimise the harmful effects on civilian populations, which were typical of comprehensive economic sanctions. Measures such as travel bans and asset freezes enable the UN and others to target individuals and non-state entities. However, sanctions – even targeted ones – are not precision tools and their impact varies widely. They are sometimes perceived (and used) as symbolic sanctions and their main impact is stigmatisation: 'naming and shaming' targets rather than impeding their activities or extracting direct concessions. Even if mainly symbolic, the imposition of sanctions can have a powerful effect in signalling international disapproval of those violating international norms.
While sanctions are never sufficient as a conflict resolution tool (not themselves addressing the root causes of a conflict or the need for dialogue and problem-solving), they may play a role in a conflict resolution process, as explored in the next chapter. The threat of sanctions may be influential in deterring egregious and escalatory behaviour. In some cases they sufficiently weaken parties' strategic military, economic or diplomatic position so that they recognise they have more to gain by entering the process than by eschewing it, as seen in Sudan and Côte d'Ivoire.
As Risse, Ropp and Sikkink have argued, sanctions, especially those originating in civil society, may have a 'socialising' effect. They send the message that if particular behaviour persists then the target may be excluded from its chosen 'reference group' (such as the 'West' or the 'international community'). Even if the parties enter into talks simply to simulate compliance with international pressure, engaging in 'talking the talk' of compromise, human rights and peace may ultimately have a deeper-rooted impact upon conflict-affected societies than initially assumed, as the South Africa case reveals.
Yet sanctions are rarely crafted as an element of a strategic conflict resolution framework. As such, they often have a number of unintended consequences on the conflict – in part due to their bluntness and inflexibility on one hand and the perception of bias and inconsistency on the other. They are often perceived as bargaining chips in wider political games. Many of the cases reveal that sanctions fail to achieve specific behavioural change and inadvertently escalate conflict dynamics. They can harden or entrench conflict attitudes and behaviour, as in the 'rally-around-the-flag' effect identified by Johan Galtung. These negative effects tend to be especially strong where sanctions are popularly associated with one side's efforts to isolate and weaken an adversary, such as the Commonwealth of Independent States' sanctions on Abkhazia.
Once established, usually through a long and difficult process, lifting sanctions can be complicated. Sometimes those targeted with sanctions do not believe that they will be lifted even if they comply (as happened at certain points in Iraq and Sudan). Furthermore, while the threat of sanctions may be effective for encouraging leaders to change their approach, once applied they tend to sit heavily on a process. Often there is little reason for the parties to change tack, as they are already paying the price of isolation.
Many negative sanctions make engagement difficult or impossible, especially where they are designed without reference to specific conflicts. For example, terrorist listings, used to punish or isolate armed groups deemed to be international security threats, are also applied to many groups associated with domestic armed conflicts. While such lists express clear disapproval, they are typically perceived by the proscribed group as an attempt to de-legitimise their goals rather than their methods. This can sometimes entrench militant positions and weaken factions willing to explore a political strategy leading to conflict settlement by sealing off choices and avenues for dialogue.
The effectiveness of sanctions as a tool of persuasion seems to depend on: (a) how the leaders of the belligerent groups respond and whether they are concerned about the consequences of the sanctions on the public or themselves; (b) the credibility of the threatened sanctions and whether they will be implemented and enforced; (c) the credibility of the sanctioners and particularly whether important allies will cut off their support; and (d) the wider political context and how it has shaped the expectations of the parties.