Identify the common element in the following United Nations Resolutions: 1737 (2006), 1747 (2007), and 1803 (2008).
Iran must withdraw all its troops from neighboring Iraq.
Iran must allow western oil companies access to its oil reservoirs.
Iran must not pursue nuclear power as a source of energy.
Iran must stop enriching uranium.
Iran must pursue peaceful energy-based international relations within the framework of OPEC.