agreement that could be seen as antagonistic towards the Soviet Union would be supported by the Czechoslovak government. That was a major blow to the Polish-Czechoslovakian negotiations. Aftermath Soon afterward, Poland and the Soviet Union broke diplomatic relations over the Katyń massacre. Beneš, meanwhile, focused on pursuing a Czechoslovakia-Soviet alliance. The death of Sikorski that year was another major blow to the planned federation, as he was seen as the plan's major supporter in the international scene. In December 1943, a new Treaty of Alliance (for 20 years) was signed between the Czechoslovak government in exile and the Soviet Union in Moscow, and a Treaty of Military Co-operation between the two followed next spring. Beneš's support for the Soviet Union went so far that during his 1943 visit to the US, he argued that the Soviet Union would never be a threat to either Czechoslovakia or Poland. Beneš probably saw the threat of identity loss for Czechoslovakia and the Czechoslovak people in such a federation as more likely than the threat of a conflict or takeover by the Soviet Union, which he perceived as a benevolent ally. In the end, the Polish federation plan came to naught; instead, the short-term victory with regard to the Central and Eastern European geopolitical scene went to Beneš, and in the long term, it went to his Soviet allies. Czechoslovakia would regain most of the disputed Zaolzie territory, but by 1948, both it and Poland would have only nominal independence, as they would fall to communist takeovers and become part of the Soviet sphere of influence. Beneš died in 1948, soon after the communists took power in the Czechoslovak coup d'état of 1948 and forced him to retire from politics. See also Greek–Yugoslav confederation Union of Hungary and Romania Notes a As the details of the planned union were never finalized, it is not clear whether it would have been a federation or a confederation. Sources use both the term "Polish-Czechoslovakian federation" and the term "Polish-Czechoslovakian confederation". References Further reading Konfederacja polsko-czechosłowacka: dokumenty (Polish-Czechoslovakian confederation - documents). Wandycz, Piotr. Zeszyty Historyczne, 116, 1996, p. 186-90. Proposed political unions Czechoslovakia–Poland relations Federalism by country Poland in World War II Politics of Czechoslovakia Political history of Poland Intermarium