Peacekeeping
Being a contributor to peacekeeping missions also provides some international prestige for developing countries, and can bolster countries' claims to be a great power as in the case of Brazil and India. Lastly, providing peacekeepers can have financial benefits for poorer countries. The monthly rate of reimbursement per peacekeeper includes $1,028 for pay and allowances; $303 supplementary pay for specialists; $68 for personal clothing, gear and equipment; and $5 for personal weaponry. Both the direct payments and the training and equipment provided by UN peacekeeping missions can be financially attractive to individual soldiers and developing nations. About 4.5% of the troops and civilian police deployed in UN peacekeeping missions come from the European Union and less than one percent from the United States.
With regard to mission leadership, Force Commanders often come from large troop contributors, while the Special Representatives of the Secretary General often come from developed countries.

Women's participation in peacekeeping: Security Council Resolution 1325 was the first major step taken by the UN to include women as active and equal actors in “the prevention and resolution of conflicts, peace negotiations, peace-building, peacekeeping, humanitarian response and in post-conflict reconstruction and stresses the importance of their equal participation and full involvement in all efforts for the maintenance and promotion of peace and security”. A critique of this resolution is that UNSCR 1325 proposes the implementing gender mainstreaming, however the progress that has been accomplished in this area has focused on women, rather than on assessing the impacts of planned action on both men and women. In 2010, a comprehensive 10-year impact study was conducted to assess the success of this resolution and found that there was limited success with the implementation, particularly in the increasing women's participation in peace negotiations and peace agreements, and sexual and gender-based violence has continued to be prevalent, despite efforts to reduce it.

In 2013 the U.N. Security Council unanimously passed Resolution 2122, which among other things calls for stronger measures regarding women's participation in conflict and post-conflict processes such as peace talks, gender expertise in peacekeeping missions, improved information about the impact of armed conflict on women, and more direct briefing to the Council on progress in these areas. Also in 2013, the Committee on the Elimination of Discrimination against Women (CEDAW), a UN women's rights committee, said in a general recommendation that states that have ratified the UN Women's Rights Convention are obliged to uphold women's rights before, during, and after conflict when they are directly involved in fighting, and/or are providing peacekeeping troops or donor assistance for conflict prevention, humanitarian aid or post-conflict reconstruction The Committee also stated that ratifying states should exercise due diligence in ensuring that non-state actors, such as armed groups and private security contractors, be held accountable for crimes against women.
As of July 2016, women serve in every UN peacekeeping mission either as troops, police, or civilian staff. In 1993, women made up 1% of deployed uniformed personnel. In 2020, out of approximately 95,000 peacekeepers, women constituted 4.8% of military personnel, 10.9% of police personnel, and 34% of justice and corrections personnel in UN peacekeeping missions. As of September 2021, no state contributing more than 100 UN peacekeepers nominates more than 25% women; in absolute numbers, the largest female contingents are provided by Ethiopia (578 female peacekeepers, or 12% of its total forces), Rwanda (500/10%), and Ghana (389/17%). While there is no set target for the proportion of women among military personnel, the UN is requesting contributing states to nominate a minimum of 20% women for policer officer positions and 30% for justice and corrections personnel. In 2023, both the number and the proportion of women in the military personnel of UN peace operations increased. This trend has continued since the launch of the Uniformed Gender Parity Strategy. In June 2023, women constituted 7.3% of the total military personnel deployed in UN peace operations, which was an increase of 0.6% compared with the previous year.

Theoretical basis for peacekeeping: While much has been written about peacekeeping and what peacekeepers do, very little empirical research has taken place in order to identify the manner in which peacekeepers can have an impact in a post-conflict environment. Columbia University Professor Virginia Page Fortna attempted to categorize four causal mechanisms through which peacekeepers have the opportunity to lay the groundwork for a lasting peace. Fortna's four mechanisms are as follows:

Change the incentives of recent belligerents, making peace more desirable or war more costly.
Reduce the uncertainty and fear that drives security dilemma spirals.
Prevent or control accidents or the actions of rogue groups that might otherwise escalate back to war.
Prevent political abuse by one side (generally the government) that might cause actors losing the peace to take up arms anew.
Fortna argues that peacekeepers have a positive impact on the peace process, despite often being sent to places where peace is most difficult to achieve. Peacekeeping is often looked at by detractors as ineffective, or unnecessary. Peace prevails when belligerents already have a vested interest in sustaining peace and therefore it could be argued that Peacekeepers play only a minor role in creating a strong foundation for enduring peace. Yet these causal reasons illustrate the important roles that Peacekeepers play in ensuring that peace lasts, especially when contrasted against situations in which belligerents are left to their own devices. These causal reasons thus illustrate the need for Peacekeeping and lay a foundation for the manner in which Peacekeeping operations can have a substantive impact on the post-conflict environment.
In order to change the incentives for war and make peace more appealing the UN can provide a military force by way of an enforcement mandate which provides deterrence to would-be spoilers. They can monitor the situation making the potential for surprise attack by one of the belligerents less likely to occur or by making it more difficult to carry out such an attack. A lightly-armed observer mission can also serve as an early-warning force or "tripwire" for the aforementioned enforcement mission. Aid and recognition provided to the belligerents by the international community should be made conditional and based on compliance with objectives laid out in the negotiating process. And lastly, peace dividends should be provided in the forms of jobs, public works and other benefits.
To reduce uncertainty and fear the UN Peacekeeping force can monitor the aforementioned compliance, facilitate communication between belligerents in order to ease security dilemma concerns thus reassuring belligerents that the other side will not renege, and allow for belligerents to signal their legitimate intentions for peace to the other side. That is to say, provide a meaningful pathway for communication between both sides to make their intentions known and credible.
Prevention and control of potential accidents that may derail the peace process can be achieved by the peacekeeping force by deterring rogue groups. Belligerent forces are often undisciplined without a strong central source of command and control, therefore while a peace is being negotiated there is potential for a rogue group on one side to renege and spoil the peace process. UN forces can serve to prevent this. Additionally, the UN force can serve as a moderator and make communication easy between both parties and bring in political moderates from either side. By providing law and order UN peacekeeping forces can temporarily replace a state's security forces and prevent a bias overreaction to an alleged violation by one side which could in turn result in escalation and a renewal in the violence.
Prevention of political abuse can be achieved through the reformation of institutions associated with the government. Training and monitoring the security forces (e.g. army or police) help to make them an unbiased protector of the people rather than a weapon of suppression for the ruling government. Hopefully this training can bring trust by the people for the security establishment. UN forces can also run and monitor elections in order to ensure a fair process. In other cases, the UN may provide a neutral interim government to administer the country during a transitional period wherein the associated government institutions are being retrained, reformed or better developed. Lastly, military groups such as armed rebels can be encouraged to put down their weapons and transformed into political organisations using appropriate non-violent means to mete out their grievances and compete in the election cycle. This is especially important as many of these groups serve as the chief opposition to a given government, but lack the means or know-how to operate effectively as political organisations.
Different peacekeeping missions take place as a result of different causal mechanisms. More military deterrence and enforcement are meant for those missions operating under the auspices of Chapter VII, while Chapter VI missions are meant to serve more as monitoring forces and interpositional operations are meant to target and prevent potential political abuse—these are primarily multidimensional missions and are heavily involved in the post-conflict political situation.

Effectiveness of peacekeeping missions: Reviews of the academic literature show considerable evidence that peacekeeping increases peace. According to Fortna, there is strong evidence that the presence of peacekeepers significantly reduces the risk of renewed warfare; more peacekeeping troops contribute to fewer battlefield deaths; and more peacekeeping troops contribute to fewer civilian deaths. A study by political scientists at Uppsala University and Peace Research Institute Oslo estimates that an ambitious UN peacekeeping policy with a doubled peacekeeping operation and strong mandates would "reduce the global incidence of armed conflict by two thirds relative to a no-PKO scenario." According to Fordham University political scientist Anjali Dayal, "Scholars have found that peacekeeping keeps wars from bleeding across borders.