Question: When did the country the top-ranking Warsaw Pact operatives came from, despite it being headquartered in the country known as the nobilities commonwealth, agree to a unified Germany inside NATO?

Knowledge 1: Szlachta
The Polish nobility enjoyed many rights that were not available to the noble classes of other countries and, typically, each new monarch conceded them further privileges. Those privileges became the basis of the Golden Liberty in the Polish–Lithuanian Commonwealth. Despite having a king, Poland was called the nobility's Commonwealth because the king was elected by all interested members of hereditary nobility and Poland was considered to be the property of this class, not of the king or the ruling dynasty. This state of affairs grew up in part because of the extinction of the male-line descendants of the old royal dynasty (first the Piasts, then the Jagiellons), and the selection by the nobility of the Polish king from among the dynasty's female-line descendants. [SEP] Knowledge 2: Warsaw Pact
Before creation of Warsaw Pact, fearing Germany rearmed, Czechoslovak leadership sought to create security pact with East Germany and Poland. These states protested strongly against re-militarization of West Germany. The Warsaw Pact was primarily put in place as a consequence of the rearming of West Germany inside NATO. Soviet leaders, as many European countries in both western and eastern side, feared Germany being once again a military power as a direct threat and German militarism remained a fresh memory among Soviets and Eastern Europeans. As Soviet Union had already bilateral treaties with all of its eastern satellites, the Pact has been long considered 'superfluous', and because of the rushed way in which it was conceived, NATO officials labeled it as a 'cardboard castle'. Previously, in March 1954, the USSR, fearing the restoration of German Militarism in West Germany, requested admission to NATO. [SEP] Knowledge 3: Society of Communist Czechoslovakia
Czechoslovakia, of all the East European countries, entered the postwar era with a relatively balanced social structure and an equitable distribution of resources. Despite some poverty, overall it was a country of relatively well-off workers, small-scale producers, farmers, and a substantial middle class. Nearly half the population was in the middle-income bracket. Ironically, perhaps, it was balanced and relatively prosperous Czechoslovakia that carried nationalization and income redistribution further than any other East European country. By the mid-1960s, the complaint was that leveling had gone too far. Earning differentials between blue-collar and white-collar workers were lower than in any other country in Eastern Europe. Further, equitable income distribution was combined in the late 1970s with relative prosperity. Along with East Germany and Hungary, Czechoslovakia enjoyed one of the highest standards of living of any of the Warsaw Pact countries through the 1980s.
Knowledge 1: Szlachta
The Polish nobility enjoyed many rights that were not available to the noble classes of other countries and, typically, each new monarch conceded them further privileges. Those privileges became the basis of the Golden Liberty in the Polish–Lithuanian Commonwealth. Despite having a king, Poland was called the nobility's Commonwealth because the king was elected by all interested members of hereditary nobility and Poland was considered to be the property of this class, not of the king or the ruling dynasty. This state of affairs grew up in part because of the extinction of the male-line descendants of the old royal dynasty (first the Piasts, then the Jagiellons), and the selection by the nobility of the Polish king from among the dynasty's female-line descendants. [SEP] Knowledge 2: Warsaw Pact
Before creation of Warsaw Pact, fearing Germany rearmed, Czechoslovak leadership sought to create security pact with East Germany and Poland. These states protested strongly against re-militarization of West Germany. The Warsaw Pact was primarily put in place as a consequence of the rearming of West Germany inside NATO. Soviet leaders, as many European countries in both western and eastern side, feared Germany being once again a military power as a direct threat and German militarism remained a fresh memory among Soviets and Eastern Europeans. As Soviet Union had already bilateral treaties with all of its eastern satellites, the Pact has been long considered 'superfluous', and because of the rushed way in which it was conceived, NATO officials labeled it as a 'cardboard castle'. Previously, in March 1954, the USSR, fearing the restoration of German Militarism in West Germany, requested admission to NATO. [SEP] Knowledge 3: German reunification
Horst Teltschik, Kohl's foreign policy advisor, later recalled that Germany would have paid ``100 billion deutschmarks ''if the Soviets demanded it. The USSR did not make such great demands, however, with Gorbachev stating in February 1990 that`` The Germans must decide for themselves what path they choose to follow''. In May 1990 he repeated his remark in the context of NATO membership while meeting Bush, amazing both the Americans and Germans. This removed the last significant roadblock to Germany being free to choose its international alignments, though Kohl made no secret that he intended for the reunified Germany to inherit West Germany's seats in NATO and the EC.
Knowledge 1: Szlachta
Poland's nobility were also more numerous than those of all other European countries, constituting some 10–12% of the total population of historic Polish–Lithuanian Commonwealth also some 10–12% among ethnic Poles on ethnic Polish lands (part of Commonwealth), but up to 25% of all Poles worldwide (szlachta could dispose more of resources to travels and/or conquering), while in some poorer regions (e.g., Mazowsze, the area centred on Warsaw) nearly 30%. However, according to  szlachta comprised around 8% of the total population in 1791 (up from 6.6% in the 16th century), and no more than 16% of the Roman Catholic (mostly ethnically Polish) population. It should be noted, though, that Polish szlachta usually incorporated most local nobility from the areas that were absorbed by Poland–Lithuania (Ruthenian boyars, Livonian nobles, etc.) By contrast, the nobilities of other European countries, except for Spain, amounted to a mere 1–3%, however the era of sovereign rules of Polish nobility ended earlier than in other countries (excluding France) yet in 1795 (see: Partitions of Poland), since then their legitimation and future fate depended on legislature and procedures of Russian Empire, Kingdom of Prussia or Habsburg Monarchy. Gradually their privileges were under further limitations to be completely dissolved by March Constitution of Poland in 1921. [SEP] Knowledge 2: Szlachta
Prior to the Reformation, the Polish nobility were mostly either Roman Catholic or Orthodox with a small group of Muslims. Many families, however, soon adopted the Reformed faiths. After the Counter-Reformation, when the Roman Catholic Church regained power in Poland, the nobility became almost exclusively Catholic, despite the fact that Roman Catholicism was not the majority religion in Commonwealth (the Catholic and Orthodox churches each accounted for some 40% of all citizens population, with the remaining 20% being Jews or members of Protestant denominations). In the 18th century, many followers of Jacob Frank joined the ranks of Jewish-descended Polish gentry. Although Jewish religion wasn't usually a pretext to block or deprive of noble status, some laws favoured religious conversion from Judaism to Christianity (see: Neophyte) by rewarding it with ennoblement. [SEP] Knowledge 3: Warsaw Pact
The Warsaw Treaty's organization was two-fold: the Political Consultative Committee handled political matters, and the Combined Command of Pact Armed Forces controlled the assigned multi-national forces, with headquarters in Warsaw, Poland. Furthermore, the Supreme Commander of the Unified Armed Forces of the Warsaw Treaty Organization which commands and controls all the military forces of the member countries was also a First Deputy Minister of Defense of the USSR, and the Chief of Combined Staff of the Unified Armed Forces of the Warsaw Treaty Organization was also a First Deputy Chief of the General Staff of the Armed Forces of the USSR. Therefore, although ostensibly an international collective security alliance, the USSR dominated the Warsaw Treaty armed forces.

Answer: May 1990