This a timeline of the main events of the Cold War, a state of political and military tension after World War II between powers in the Western Bloc (the United States, it's NATO allies and others) and powers in the Eastern Bloc (the Soviet Union, its allies in the Warsaw Pact and later the People's Republic of China).
Encounter at the Elbe (in Russian: Встреча на Эльбе ) is a Soviet movie released in 1949 from Mosfilm, describing the conflict, spying, and collaboration between the Soviet Army advancing from the east and the U.S. Army advancing from the west.
 The two allied forces met each other for the first time on the River Elbe near the close of the Second World War.
 This meeting occurred on April 25, 1945, which was usually remembered as “Elbe Day” in Western Bloc nations and as the "Encounter at the Elbe” in Eastern Bloc nations.
Eastern Bloc politics followed the Red Army's occupation of much of eastern Europe at the end of World War II and the Soviet Union's installation of Soviet-controlled Stalinist or Marxist–Leninist governments in the Eastern Bloc through a process of "bloc politics" and repression.
 The resulting governments contained vestiges of western democracies to initially conceal the process.
The Republic of Poland and Czechoslovakia established relations early in the interwar period, after both countries gained independence.
 Those relations were somewhat strained by the Polish–Czechoslovak border conflicts over Zaolzie and Cieszyn in the early 1920s and late 1930s ("see also Munich Agreement").
 Both countries joined the Allies during World War II.
 After the war they both fell into the Soviet sphere of influence (the Eastern Bloc).
 Poland, together with other Eastern Bloc countries, participated in the Warsaw Pact invasion of Czechoslovakia in 1968.
 Relations between the two countries were nonetheless rather amicable, but became somewhat strained in the aftermath of the rise of the Solidarity movement in Poland in 1980 and 1981, improving again afterwards.
The Western Bloc or Capitalist Bloc during the Cold War refers to the countries allied with the NATO against the Soviet Union and its allies.
 The latter were referred to as the "Eastern Bloc".
 The governments and press of the Western Bloc were more inclined to refer to themselves as the "Free World" or the "Western world".
The Cold War was a state of geopolitical tension after World War II between powers in the Eastern Bloc (the Soviet Union and its satellite states) and powers in the Western Bloc (the United States, its NATO allies and others).
 Historians do not fully agree on the dates, but a common timeframe is the period between 1947, the year the Truman Doctrine (a U.S. foreign policy pledging to aid nations threatened by Soviet expansionism) was announced, and 1991, the year the Soviet Union collapsed.
The aftermath of World War II was the beginning of an era defined by the decline of the old great powers and the rise of two superpowers: the Soviet Union (USSR) and the United States of America (USA).
 Allied during World War II, the USA and the USSR became competitors on the world stage and engaged in the Cold War, so called because it never resulted in overt, declared hot war between the two powers but was instead characterized by espionage, political subversion and proxy wars. Western Europe and Japan were rebuilt through the American Marshall Plan whereas Eastern Europe fell under the Soviet sphere of influence and eventually an "Iron Curtain".
 Europe was divided into a US-led Western Bloc and a Soviet-led Eastern Bloc.
 Internationally, alliances with the two blocs gradually shifted, with some nations trying to stay out of the Cold War through the Non-Aligned Movement.
 The Cold War also saw a nuclear arms race between the two superpowers; part of the reason that the Cold War never became a "hot" war was that the Soviet Union and the United States had nuclear deterrents against each other, leading to a mutually assured destruction standoff.
Cold War II (also called the New Cold War, Second Cold War and Cold War 2.0) refers to a renewed state of political and military tension between opposing geopolitical power-blocs, with one bloc typically reported as being led by Russia and/or China, and the other led by the United States or NATO.
 This is akin to the original Cold War that saw a global confrontation between the Western Bloc led by the United States and the Eastern Bloc led by the Soviet Union, Russia's predecessor state.
 American political scientist Robert Legvold posits that the "new Cold War began the moment we went over the cliff, and that happened with the Ukraine crisis."
 Others, such as Andrew C. Kuchins in 2016, believe that the term is "unsuited to the present conflict," but the situation is arguably more dangerous than during the original Cold War.
 One of the primary features of the "New Cold War", as first defined by Philip N. Howard, is that conflict is experienced primarily over and through broadcast media, social media, and information infrastructure.
During the Cold War, a number of pilots from various nations (Eastern Bloc, Western Bloc, and non-aligned) defected with their aircraft to other countries.
According to the 2005 "Report", the world saw a shift in global security after the end of the Cold War, with a 40% decrease in the number of armed conflicts being waged around the world since the early 1990s, and an 80% decrease of genocides between 1998 and 2001.

Question: What Report reported a 40% decrease in the number of armed conflicts being waged around the world once the state of geopolitical tension after World War II between powers in the Eastern Bloc and powers in the Western Bloc came to a close?
Answer: 2005 "Report"