sentences:  Thus the formal proposal for establishing a nuclear-free region was delayed until the 1990s, after the Cold War ended and conflicts were settled, and the member states renewed the denuclearization efforts.After conducting negotiations and finalizing the treaty for SEANWFZ by an ASEAN working group, the SEANWFZ treaty finally signed by the heads of government from 10 ASEAN member states in Bangkok on December 15, 1995.The treaty took effect on 28 March 1997 after all but one of the member states have ratified it.