- Peter is a long-time resident of Townshend, Vermont.
- In 1993, Peter was appointed the first U.S. Ambassador to Croatia. He negotiated the peace agreement that ended the Croatian War in 1995 and was part of the negotiating team that ended the Bosnian War that same year.
- Peter was chair of the Vermont Democratic Party from 1977-1979 - he was chair when Gov. Madeleine Kunin was first elected Lieutenant Governor.
- Peter worked full time for Gov. Phil Hoff's 1970 Senate campaign, going door-to-door throughout Windham County.
- Peter was a delegate for George McGovern to the 1972 National Democratic Convention from Vermont. He was co-chair of Morris Udall's Vermont campaign in 1976 and was a Udall delegate to the National Convention that year.
- Peter wrote the critically acclaimed national best seller The End of Iraq: How American Incompetence Created a War without End.
- Peter was effectively the deputy administrator of East Timor when the United Nations ran the country. In that role, he helped rebuild the economy and the country's infrastructure, created jobs and designed the first transitional government and the process to write East Timor's permanent constitution. The East Timorese made him a member of the country's first cabinet and he created East Timor's National Park System.
- In 1983, Peter wrote the principal U.S. legislation to protect biological diversity worldwide and was twice a member of the U.S. delegation to the U.N. Environment Program Governing Council - Indeed, he's won awards for his work to protect the international environment.
- Peter is the principal in Windham Resources Group, LLC, an international business based in Windham County.
- Prior to being appointed Ambassador, Peter served as Senior Advisor to the U.S. Senate Foreign Relations Committee. Among many other things, he exposed Saddam's genocide against the Kurds and led the Senate to pass severe sanctions against Iraq.
- Pakistan awarded Peter its highest civilian award in recognition of his work to promote human rights and restore democracy.
- Four days after the first American troops arrived in Baghdad in 2003, Peter arrived as an ABC news consultant.