The prevention is an activity taking place before the conflict while the other four are carried out after the eruption of armed fighting. Conflict prevention comprises the employment of structural or diplomatic measures to prevent disputes from escalating into violent conflict.

Intervention is an act of involvement, whether intentionally or not, in a difficult conflict situation to improve or prevent something getting worse. Intervention requires a comprehensive program with its new types of economics, commerce, military and politics fields.

There are three differing kinds of peace
operations:

traditional peace keeping (Cold War),
humanitarian military intervention (1990s), 
new generation peace operations (2000s) (Cottey,
2008: 429, 432).

International intervention, particularly, humanitarian one, is the focus of international debate across a variety of international bodies and academic fields. International relations, political science, international and national comparative law, and political philosophy are the main fields which discuss the humanitarian intervention.

During the 1990s, intervention took places in “no-fly zones” in Iraq, Somalia, Bosnia, Sierra Leone, East Timor and Kosovo.

Sovereignty means a central governing authority within a specified geographical territory,combined with the recognition of its status by other states conferring on the state sovereignty.

The theory of national self-determination is “peoples” have a right to determine the shape of their association,
including the political association.

(a) the breakup of a sovereign state caused by the secession of one faction from the rest;

(b)where a country has already been invaded and third parties face the question of counter-intervention;

(c) when the violation of human rights within a set of boundaries is so terrible that it makes talk of community or self-determination or arduous struggle seem cynical and irrelevant, that is, in cases of enslavement or massacre’ (Walzer, 1977: 90).

One of the most cited definition, Adam Roberts (1993, p.429) points out that humanitarian intervention is “coercive action by one or more states involving the use of armed force in another state without the consent of its authorities, and with the purpose of preventing widespread suffering or death among the inhabitants”.

Pattison (2010: 28) puts forth a comprehensive definition that intervention is “forcible military action by an external agent in the relevant political community with the predominant purpose of preventing, reducing, or
halting an ongoing or impending grievous suffering or loss of life.”

1. It comprises use of force, particularly military elements.

2. Humanitarian intervention must lack the consent of the government of the target state.

3. It takes place where there is actual or impending grievous suffering or loss of life.

4. External agent should carry out humanitarian intervention.

5. Humanitarian intervention must have a humanitarian intention.

6. The Security Council authorization is required.

The most important actors in the international system are states, whose primary objective and motive is to protect their sovereignty (Sönmezoğlu, 2005: 17-33).

Responsibility to protect doctrine was endorsed at the 2005 World Summit whose final document declared
that “the international community, through the United Nations, also has the responsibility to use the appropriate diplomatic, humanitarian and other peaceful means… to protect populations from genocide, war crimes, ethnic cleansing and crimes against humanity”.

Secondly, the new type of peacekeeping operations undertaken since the 1990s blurred the boundary between
peacekeeping and humanitarian intervention.

Thirdly, the regionalization of peace operations
emerged in the 1990s are continuing to operate
in the grey area between traditional peacekeeping,
humanitarian intervention and nation-building
(Cottey, 2008: 431).

The UN capstone document, “Peacekeeping Operations: Principle and Guidelines”, divides peace operations into
five elements as conflict prevention, peacemaking, peacekeeping, peace enforcement, and peacebuilding.

Conflict prevention, also known as preventive diplomacy, is the endeavor taking place. It
involves the utilization of structural or diplomatic measures to prevent intra-state or inter-state tensions
and disputes from escalating into violent conflict (UN Peacekeeping Operations, 2008: 17). 

Peacemaking includes measures to address ongoing conflicts and usually comprises diplomatic action and mediation to bring hostile parties to a negotiated agreement (UN Peacekeeping Operations, 2008, p.17).

The basic goals of peacemaking are to help ending armed conflict and organizing the conditions in the aftermath for the reconciliation of warring parties. It involves ‘the stationing of neutral, lightly armed troops with the permission of the host state(s) as an interposition force following a cease-fire to separate combatants
and promote an environment suitable for conflict resolution’ (Diehl, 2008: 15).

The peace operations are examined in two categories :

1.peacekeeping and political missions  

2.political missions.

The evolution of peace operations can be divided into three basic phases as the period before the League of Nations (antecedents), the League of Nations phase (novice attempts), and the current period beginning after the founding of the United Nations (maturity).

The peace building operations aim to reform the conditions underlining unsecure environment. These missions include many related activities from helping to build sustainable institutions of governance to human rights monitoring; security sector reform; disarmament, demobilization and reintegration of former combatants. So, the peace programs should not only aim to suppress violence, but also exert efforts to eliminate or relieve the
underlining conditions.