Sources

• International legitimacy can come from international organizations such as the United Nations and the International Red Cross. It can also come in the form of support from individual countries.
  
  

Domestic Support

• International legitimacy has tremendous impact on a country's domestic politics. For example, if a country does not have legitimacy, domestic forces within the country will have more power in stopping the action. An example of this would be the effectiveness of the U.S. anti-war movement during Vietnam.
  
  

Security

• A lack of international legitimacy might make acts of terrorism a more effective strategy to sway public opinion. The Madrid bombings of 2004 during the Iraq War were successful in shifting public opinion against Spain's involvement in the war on terror.
  
  

Funding

• States that want to pursue an intervention operation but don't have international legitimacy may have fewer allies who will be able to help carry the burden of intervention.
  
  

Effectiveness

• Lack of international legitimacy can also make an action more difficult to pursue because the local population might see the country as an aggressor and choose not to cooperate.