This article examines some international factors contributing to the r
ecent spread of preferential trading arrangements (PTAs). PTAs help st
ates to ensure against future disruptions of commerce with key trade p
artners. When stress is placed on the international trading system, th
e threat of such disruptions rises. Both hegemonic decline and global
recessions raise the specter of commercial closure, and therefore each
factor may stimulate the proliferation of PTAs. Furthermore, strategi
c interaction among both PTAs and countries is likely to guide the gro
wth of preferential arrangements. As PTAs become increasingly pervasiv
e, states that are not covered by one have strong incentives to enter
such an arrangement. Doing so reduces the prospect that their access t
o important markets will be curtailed and that their competitiveness a
broad will be undermined. The findings of this article conform with th
ese arguments. In general, eroding hegemony, global recessions, and st
rategic interdependence have accelerated the pace of commercial region
alism since World War II.