Complex sentence: Additionally, they argue that the U.N. rejected the invasion of Iraq because of their involvement in the "Oil for Food Scandal", (established in 1995), in which U.N. and Iraqi officials skimmed money to allegedly bribe U.N. officials.
Split into simpler sentences: Additionally, they argue that the U.N. rejected the invasion of Iraq because of their involvement in the "Oil for Food Scandal," (established in 1995). In which U.N. and Iraqi officials skimmed money to allegedly bribe U.N. officials.