The UN's peacekeeping army of 112,000 troops, would be much less effective, were not for the British Empire. About a third of those peacekeepers come from nations that were formerly part of the British Empire (mostly from what used to be British India; India, Pakistan, Bangladesh, Nepal.) To maintain and protect is empire, the British recruited lots of local troops, and trained them as they would British soldiers. While most of the officers were British, most of the NCOs were locals. Before the British relinquished its colonies after World War II, it also trained many locals as officers. Much of this Western training and military traditions took hold, especially in South Asia. The British encountered some formidable local armies when they moved into India three centuries ago. But the British had better technology and more advanced military doctrine. The Indians noted this, and some of the local rulers quickly, but not quickly enough, adopted the superior British practices. When the British left, the South Asian armies remained very British in the way they trained and operated. That meant well trained and well led troops, but without all the gadgets that Western nations lavish on their soldiers. For peacekeeping, the disciplined and reliable South Asian soldiers are excellent peacekeepers. Those from other less affluent nations often lack the discipline and good leadership, and account for most of the peacekeeping scandals.
Meanwhile, corruption, casualties and lack of success are discouraging countries from contributing their troops for peacekeeping. The corruption angle is interesting, as it pertains both to the corruption within the UN bureaucracy, and the corrupt atmosphere the peacekeepers operate in, and often succumb to. Casualties are expected, but the contributing countries feel a lot of their troop losses are the result of restrictive UN rules that limit what peacekeepers can do. This, in turn, is believed most responsible for a lack of success for the peacekeeping missions.
India, Bangladesh and Pakistan (who contribute nearly a quarter of the UN force) are not happy with the lack of volunteers from other major nations. The chief reasons for that are the same ones annoying the current peacekeepers (corruption and restrictive rules of engagement). In addition, the major military powers (with the exception of China and Russia) feel they already contribute quite a lot in the form of money to pay the peacekeepers. And the contributors are also upset at the lack of results.
The UN will spend about $8 billion on fifteen peacekeeping operations this year. This pays for a force of over 112,000 troops and support staff. It's actually a pretty cheap way of keeping some conflicts under control. The causes of the unrest may not be resolved by peacekeepers, but at least the problem is contained and doesn't bother the rest of the world too much. This is an increasingly unpopular approach to peacekeeping, except in the UN bureaucracy. Many UN members would rather send peacekeepers to where they are not wanted (by the government, usually a bad one, that is often the cause of the trouble in the first place.)
Most of the money is going to a few large peacekeeping operations. Three of the largest (Congo, Darfur and south Sudan) get over half the cash. Africa has the largest number of "failed states" on the planet and, as such, is most in need of outside security assistance. The Middle East is also a source of much unrest. But there the problem isn't a lack of government, just bad government. Most Middle Eastern nations are run by tyrants, who have created police states that at least keep anarchy at bay.