UNRWA

United Nations Relief and Works Agency for Palestine (UNRWA) was created in December 1949. Originally designed for helping both Jewish and Arab refugees of 1948 war both inside and outside the State of Israel it ceased operations inside Israel in 1952 when Israel took whole responsibility for these of her residents/ citizens who used to be refugees.
Originally undoubtedly UNRWA was trying to base it actions on UNRRA experience, as United Nations Relief and Rehabilitation Organization, funded in 1943, included in UN in 1945 (after it was established) was especially active in 1945 and 1946 and dismantled in 1947.
Only in 1950 did UN establish its agenda designed to deal generally with refugees from all conflicts (UNHCR) and defined who is (and who is not) a refugee and what expectations should be meet by the agenda, but it never unified UNRWA and UNHCR definitions, goals and methods of dealing with problem thus creating very special "cast" among all touched by results of conflicts and border changes. Palestinian "refugees" (of whom majority would never been recognized as such by UNHCR at this time) receive the global highest financial help per capita, are entitled to inherit their status (which vastly adds to the problem) and are absolutely convinced (at least in great part) about UN backed so called "right of return" being in sharp contrast with any rights of any refugees anywhere else.

Let us look more closely at the problem.

1. Palestinians inheriting their refugee status: originally according to different sources there has been between 500,000 and 750,000 Arab refugees of 1948 conflict. Most sources put the number at approximately 650,000 people. Today UNRWA claims to take care about more than 5 million refugees. No other group of refugees ever has been entitled to pass this status to their children and grandchildren. Let us try to explore what would it mean if Palestinian Arabs were treated equally:

• there seem to be between 35,000 and 40,000 people who actually were refugees from the conflict still living. I have no idea how many are living at the UNRWA controlled facilities yet taking (even very good) care about 40,000 old people hardly requires special UN agenda with billion dollar budget and 30,000 regular employees Most of the refugees from around the same time would not be recognized as such by anybody anyway. Let us try: 
• after II WW there where around 5 million Russian displaced persons, as a result of changing borders you can add some 2-3 million Poles, 2 million Germans, many Ukrainians, Lithuanians, Latvians, Estonians and of course virtually all Jews who survived! Their grandchildren constitute vast number of EU citizens and do not expect anybody to pay them for the horrors their grandparents went through.
•  There were some 900,000 Jewish refugees of 1948 conflict mostly evicted from all Arab countries, often without any possessions and after being jailed or even tortured. Their fell out of UNRWA attention at most in 1952 and their grandchildren do not carry "refugee" label or demand international money and "right of return" to wherever it was their grandparents were forced from.
•  Tibetan refugees from occupation of Tibet by China (lasting since 1950) have this status only until some solution can be found. UNHCR on the basis of Gentleman Agreement with the government of Nepal mostly works towards resettling them there and none of their children or grandchildren is treated as "refugee" although their bonds with Tibet are obvious for everybody
• and there were Congo and Angola and South Sudan and Rwanda and Cambodia and.... yeah, we know

2.  Palestinian refugees were denied citizenship in Syria, Lebanon and in Jordan.  They were admitted to the latter country bu then evicted or stripped of residency after Black September tried to overturn Hashemide dynasty in 1970. And who could blame Jordanians? None of us would watch willingly as refugees try to take control of the host country by force. In Syria and Lebanon they were used by Arab politics hostile towards Israel to show as Israeli atrocity but it is not Israeli fault that they were not allowed to live outside refugee camps, were deprived of right to study or take a job  etc. UNRWA is trying to take care of some of the problems (there are 59 UNRWA sponsored towns and villages dispersed on Palestinian, Lebanese and Syrian controlled territory with one in Israeli hold territory). Palestinian refugees are offered the highest per capita financial help in the world which - by the way - may be precarious now that Syria has over 3 million refugees (according to UNHCR definition meaning many more than Palestinians ever had) who are under UNHCR protection. Thus we have two different categories of refugees in one country with different level of financing from UN and different UN agendas tending to them.

3. UNHCR  has stated three equivalent solutions for refugees: voluntary repatriation; local integration; or resettlement to a third country in situations where it is impossible for a person to go back home or remain in the host country. It regards ALL but Palestinian refugees. UNRWA, by contrast, emphasizes "right of return", as understood by by Arab propaganda, consequently preventing people from rebuilding their lives and creating them for their children, be it in Palestinian controlled territories or anywhere else. Instead, people are kept in a state of dreaming about "return" to someplace that only their grandparents might have seen. They live the dream and raise their kids to fulfill it with murder and sacrificing their lives, if need be. As it goes for generations it may be compared to third generation of Germans whose grandparents were forced out of Czechoslovakia or Romania or Poland after the war. If they were living just dreaming about going someday - maybe in 2-3 generations - "home" their presence in contemporary Europe would have been like time-bomb. Specially had they preserved Nazi views and had on average 5 children per woman. The same goes for Poles forced of their homes due to change of borders with Soviet Union in 1945 or the Irish forced out of Home Island by Great Famine and now their descendants dreaming about taking both islands (UK included) because it was their "home". Would we feed such dreams or step back in horror? 

There is one more problem with UNRWA: it is an old organization. With workforce of over 30,000 people, mostly Palestinians who live out of donations to it it is now "a nation of its own" as someone has described it. To many people with their families and status depend on preserving status quo: same stories, same propaganda, same life-patterns, same dependency. They were taught it and taught very well. They adapted to this situation and as all of us knowing some kind of situation with its upsides and downsides are familiar with it and they dread changes, even for good, because one has to adapt to changes, change the way of thinking and behaving and solving problems. This could be seen in former communist countries where people, even dreaming about a change found it challenging because they had to adapt to new realities, find their ways, take new responsibilities, learn new tricks (like an old dog). In UNRWA controlled  settlements very few are ready for a challenge of changes - even ones for better for them and their neighbors. And maybe this preservation of mentality (we will fight, kill, be killed, one day return, murder all Jews, our home is someplace else) by obstructing forces that would move these people into different patterns is the worst thing UNRWA does - to both Palestinians and Israelis.