In the 1980s, Papoulias played a key role in trying to reach a solution to the Israeli–Palestinian conflict.
He mediated a safe departure of trapped Palestinian militants and Yasser Arafat from Lebanon on board Greek vessels in 1983.

He created diplomatic relations with the Arab world and achieved, among other things, the normalization of relations between Greece and Egypt and the establishment of tripartite cooperation between Iran, Armenia and Greece.
He held talks with a total of 12 Turkish Foreign Ministers to normalize Greco-Turkish relations.
This resulted in the signing of the Papoulias-Yılmaz memorandum in 1988.

He supported Turkey's European aspirations conditional on their respect for international law and European Union values.

In the period 1993–1996 and particularly at the crucial Essen Summit he played an important role in starting accession talks between the Republic of Cyprus and the European Union.

As president-in-office of the European Union and member of the contact group for the former Yugoslavia he worked to bring about a resolution of the crisis in Bosnia and Herzegovina.
He signed the Interim Agreement with the Former Yugoslav Republic of Macedonia, aiming at the establishment of better relations between that country and Greece.

He was very interested in relations between Greece and the Balkan states and it was upon his initiative that the first meeting of the Ministers for Foreign Affairs of the Balkans was organized in Belgrade in 1988.
There, he began talks with Bulgaria and the then Soviet Union on the Burgas-Alexandroupolis oil pipeline.

He was responsible for the signing of the protocol of mutual civil and military assistance with Bulgaria in the 1980s.
He restored friendly and neighbourly relations with Albania by ending the state of war between that country and Greece.

Papoulias has been supportive of any step towards détente, peace and disarmament e.g. the "Initiative of the Six" for peace and disarmament, the participation of Greece in the Conference on Disarmament and Peace in Europe and in the Conference for the Abolition of Chemical Weapons, his proposals to create a nuclear-free zone in the Balkans and the promotion of the idea of making the Mediterranean a sea of peace and cooperation.
The JANNINA 1 tripartite cooperation conference, between Greece, Bulgaria and Romania, was his idea and he was a strong supporter of the Black Sea Conference, which he also chaired.

With his visit to Washington in 1985 and the return visit of Secretary of State George Shultz, he revitalized Greek-American relations which had gone through a delicate phase during the previous years.
In the 1980s, Papoulias played a key role in trying to reach a solution to the Israeli–Palestinian conflict. He mediated a safe departure of trapped Palestinian militants and Yasser Arafat from Lebanon on board Greek vessels in 1983.
He created diplomatic relations with the Arab world and achieved, among other things, the normalization of relations between Greece and Egypt and the establishment of tripartite cooperation between Iran, Armenia and Greece. He held talks with a total of 12 Turkish Foreign Ministers to normalize Greco-Turkish relations. This resulted in the signing of the Papoulias-Yılmaz memorandum in 1988.
He supported Turkey's European aspirations conditional on their respect for international law and European Union values.
In the period 1993–1996 and particularly at the crucial Essen Summit he played an important role in starting accession talks between the Republic of Cyprus and the European Union.
As president-in-office of the European Union and member of the contact group for the former Yugoslavia he worked to bring about a resolution of the crisis in Bosnia and Herzegovina. He signed the Interim Agreement with the Former Yugoslav Republic of Macedonia, aiming at the establishment of better relations between that country and Greece.
He was very interested in relations between Greece and the Balkan states and it was upon his initiative that the first meeting of the Ministers for Foreign Affairs of the Balkans was organized in Belgrade in 1988. There, he began talks with Bulgaria and the then Soviet Union on the Burgas-Alexandroupolis oil pipeline.
He was responsible for the signing of the protocol of mutual civil and military assistance with Bulgaria in the 1980s. He restored friendly and neighbourly relations with Albania by ending the state of war between that country and Greece.
Papoulias has been supportive of any step towards détente, peace and disarmament e.g. the "Initiative of the Six" for peace and disarmament, the participation of Greece in the Conference on Disarmament and Peace in Europe and in the Conference for the Abolition of Chemical Weapons, his proposals to create a nuclear-free zone in the Balkans and the promotion of the idea of making the Mediterranean a sea of peace and cooperation. The JANNINA 1 tripartite cooperation conference, between Greece, Bulgaria and Romania, was his idea and he was a strong supporter of the Black Sea Conference, which he also chaired.
With his visit to Washington in 1985 and the return visit of Secretary of State George Shultz, he revitalized Greek-American relations which had gone through a delicate phase during the previous years.
Karolos Papoulias