▁to ▁be ▁a ▁grand ▁theory . ▁The ▁theory ▁see ks ▁to ▁explain ▁the ▁bro ader ▁transformation ▁of ▁regional ▁integration . ▁Liberal ▁inter g overn ment al ists ▁the or ists ▁argue ▁that ▁it ▁is ▁impossible ▁to ▁explain ▁the ▁concept ▁of ▁the ▁European ▁Union ▁with ▁a ▁single ▁factor ▁and ▁believe ▁that ▁different ▁approaches ▁or ▁theories ▁are ▁needed ▁to ▁genu in ely ▁understand ▁the ▁complexity ▁of ▁the ▁EU . ▁Liberal ▁inter g overn ment al ism ▁views ▁states ▁as ▁the ▁main ▁actors , ▁and ▁sees ▁the ▁EU ▁as ▁an ▁international ▁institution ▁that ▁can ▁be ▁studied ▁by ▁view ing ▁states ▁as ▁the ▁main ▁actors ▁in ▁a ▁situation ▁of ▁an archy , ▁where ▁each ▁state ▁ach ieves ▁their ▁goal ▁through ▁negoti ations ▁and ▁b arg aining . ▁Liberal ▁inter g overn ment al ism ▁especially ▁studies ▁the ▁process ▁of ▁these ▁negoti ations ▁and ▁b arg aining ▁between ▁EU ' s ▁member ▁states . ▁ ▁Andrew ▁Mor av cs ik ▁in ▁his ▁book ▁The ▁Cho ice ▁for ▁Europe ▁( 1 9 9 8 ) ▁defines ▁EU ▁integration : ▁" E U ▁integration ▁can ▁best ▁be ▁understood ▁as ▁a ▁series ▁of ▁rational ▁choices ▁made ▁by ▁national ▁leaders . ▁These ▁choices ▁respond ed ▁to ▁constraints ▁and ▁opportun ities ▁stem ming ▁from ▁the ▁economic ▁interests ▁relative ▁power ▁of ▁powerful ▁domestic ▁constitu ents , ▁the ▁of ▁states ▁stem ming ▁from ▁asym met rical ▁inter dep end ence , ▁and ▁the ▁role ▁of ▁institutions ▁in ▁bol ster ing ▁the ▁cred ibility ▁of ▁inter state ▁commit ments ." ▁ ▁Liberal ▁inter g overn ment