on ▁the ▁cheap .' " ▁ ▁Martin ' s ▁second ▁book , ▁Democratic ▁Comm it ments : ▁Legisl atures ▁and ▁International ▁Co operation , ▁was ▁published ▁in ▁ 2 0 0 0 . ▁Con tr ary ▁to ▁the ▁orth odox y ▁that ▁international ▁affairs ▁are ▁too ▁an arch ic ▁to ▁be ▁meaning fully ▁affected ▁by ▁the ▁internal ▁politics ▁of ▁dem ocr atic ▁states , ▁Martin ▁demonstrated ▁that ▁the ▁legisl atures ▁of ▁stable ▁dem oc ra cies ▁can ▁increase ▁the ▁cred ibility ▁of ▁the ▁commit ments ▁made ▁by ▁states ▁to ▁one ▁another , ▁which ▁fost ers ▁international ▁co operation . ▁Michael ▁Tier ney ▁summar ized ▁the ▁contribution ▁of ▁Democratic ▁Comm it ments ▁by ▁writing : ▁" when ▁you ▁finish ▁reading ▁this ▁book , ▁you ▁will ▁be ▁convinced ▁that ▁legisl atures ▁have ▁a ▁surprising ly ▁large ▁and ▁meas urable ▁impact ▁on ▁the ▁probability ▁of ▁inter state ▁co operation ▁involving ▁established ▁dem oc ra cies ". ▁Compar ing ▁Martin ' s ▁first ▁and ▁second ▁books , ▁Tier ney ▁wrote ▁that ▁" while ▁Co er ci ve ▁Co operation ▁sought ▁to ▁identify ▁the ▁system ic ▁sources ▁of ▁cred ibility , ▁Democratic ▁Comm it ments ▁expl ores ▁the ▁domestic ▁institution al ▁sources ▁of ▁cred ibility ." ▁ ▁Martin ▁has ▁also ▁been ▁an ▁author ▁or ▁an ▁editor ▁of ▁two ▁text books , ▁including ▁International ▁Institution s : ▁An ▁International ▁Organ ization ▁Re ader , ▁and ▁the ▁editor ▁of ▁several ▁volumes ▁on ▁international ▁affairs , ▁such ▁as ▁the ▁Oxford ▁Hand book ▁of ▁the ▁Polit ics ▁of ▁International ▁Trade . ▁She