Opinion was the result of not having an Attorney General to lead.  Decision supporters say no terrorism from the 7 countries.  

Benghazi:  US Embassy attacked (sovereign US soil) killing ambassador and 3 others.
Somali:  ongoing piracy only stopped by international naval effort
Sudan:  Muslim terrorist al Shabbaz (sp?) has killed thousands
Yemen:  USS Cole attacked in port by suicide boat
Syria:  Ongoing wars between Assad government,  his oppressed citizens,  Kurds,  Shiite Iraqi militias,  Iranian army,  Turk air force, ISIS, alQaeda.
Iran: Last three US Presidents tell us Iran is the font of terrorist support in muslim world.

Perhaps the US Attorney for Administration was incompetent to try the case if he couldn't come up with evidence of terror from any of the 7 nations with no working governance or  ability to verify citizens as terrorists or not.