Side is related to Cause. Cause is related to Oil. Oil is related to Iraqi. 
Contribution is derived from Contribute. Contribute is a synonym of Gift. you are likely to find Gift in/at/on Party. Party is related to Good. 
Side <--RelatedTo--> Cause <--RelatedTo--> Oil <--RelatedTo--> Iraqi 
Contribution --DerivedFrom--> Contribute <--Synonym--> Gift --AtLocation--> Party <--RelatedTo--> Good 