Are international organizations effective in shaping the behavior of the international community?

The short answer is yes, international organizations (IOs) can be highly effective in shaping the behavior of the international community.
Definitions of International Organizations
For the purpose of this answer, International Organizations will be restricted to two types:
1) International Non Governmental Organizations (INGO) 2) International Governmental Organizations (IGO)
INGOs are non-profit organizations or worldwide companies that are independent of governments. They sometimes have humanitarian objectives that address issues such as healthcare, poverty, and education. These organizations also have members who may have governmental ties but are not necessarily representatives of governments. Some well-known examples of this type of organization are International Red Cross, Save the Children, and OXFAM.
IGOs are international government organizations that are based on “formal agreements between governments, have three or more nation state members, and have a permanent secretariat.” https://www.laetusinpraesens.org/docs70s/typeap4.php The most well-known example of this type of organization is the United Nations.  
Shaping Behavior
The ability of  IOs to shape the behavior of the international community is derived in part from the members of the IO and the formal and informal agreements that they have with each other. For example, the Prime Minister of Germany, a nation state that is a member of the United Nations, has a large influence on the policies of that nation and therefore has a great deal of power to shape regional and international behavior. International organizations can shape the behavior of the international community along many lines, including political, economic and social. This is accomplished by setting agenda or directives, forming or encouraging partnerships and alliances, regulating and enforcing policy. The IOs help set the agenda for international community based on their ability to obtain first-hand data and information about a particular issue or problem. Governments and members of these organizations wield their power to then set policy objectives that their home countries agree to abide by.  When an organization, government, or other large body refuses to follow the policy mandates, the members of IOs can provide censure and a wide range of other options for enforcement.
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