The thawing of the Cold War and subsequent break up of the Soviet Union yielded a formal invitation from Mikhail Gorbachev for JDC's return to the region in 1989; 50 years after Joseph Stalin brutally expelled the organization, killing several JDC members in the process. The former Soviet Union and its largely isolated and destitute community of elderly Jewish populations quickly became—and remain—the organization's priority. A growing network of "Heseds", or Hesed Community Welfare Centers in the former Soviet Union, that JDC helped establish in local communities provided welfare assistance to a peak caseload of 250,000 elderly Jews. According to a JDC publication, "The first Hesed Center was established in 1993 in St. Petersburg by Dr. Amos Avgar of the AJJDC." Dr. Avgar began developing the Hesed Model in 1992 while leading a work of experts who sought to create "a multi-functional service model." It was Avgar who set the foundations of the Hesed Model that operates according to three main principles: Jewish values, community orientation, and voluntarism. Hesed Centers have left a profound impact on both Jewish communities and on non-Jewish circles in the FSU. To publicly and formally acknowledge this impact, the Russian Academy of Languages added in March 2000 the Hebrew word "Hesed" (хесед) to the Russian language. Today, the Hesed Community Welfare Centers is still serving 168,000 of the world's poorest Jews in the former Soviet Union (December 2008).