Russia is the largest and most important partner for Belarus both in the political and economic fields. The Treaty on Equal Rights of Citizens between Belarus and Russia was signed in December 1998, covering employment, and access to medical care and education. The two countries constitute the supranational Union State.
After the Soviet Union collapsed, the newly formed Russian state tried to maintain control over the post-Soviet space by creating, on December 8, 1991, a regional organization – the Commonwealth of Independent States (CIS). However, Belarus, as other republics in the CIS, started to drift away from Russia, which at that time was attempting to stabilize its broken economy and ties with the West. In the early 90s, Russia was concerned that its involvement in the near abroad state such as Belarus would risk the relations it was trying to build with the West. However, as NATO began to expand eastward, Russia found itself in a dire situation. On one hand, it was facing a breakup of the large geopolitical bloc it had once owned; on the other, it felt that the West was trying to isolate it from the European environment by picking up the pieces of its former empire. This led to the increasing importance of good relations with Belarus.
Flag of the Russian Soviet Federative Socialist Republic (1954–1991)
Flag of the Byelorussian Soviet Socialist Republic (1951–1991)
Mid through end of the 1990s
During the mid-1990s and especially after Alexander Lukashenko came to power in Belarus, Belarus seemed an ideal candidate for integration with Russia. Russian President Boris Yeltsin said after signing, in February 1995, the Treaty of Friendship, Good-Neighborliness and Cooperation with Belarus, that “the two nations [had] shared a common historical experience over many centuries”. That, he declared, had “created the basis for signing the treaty and other documents on deeper integration of our two countries. Among all CIS countries, Belarus has the greatest rights to such a relationship due to its geographical location, its contacts with Russia, our friendship and the progress of its reforms.”  The integration process was launched on April 2, 1996 and exactly a year later, the Union of Belarus and Russia was founded. The culmination of this process was the establishment of a Union State between the RF and Belarus on December 8, 1999.
After Vladimir Putin took office he expressed his deep dissatisfaction with the status of the relations with Belarus and criticized the 1999 treaty, the policy he had set was to put real content into this treaty. His proposal was to continue in the unification either in a federation model which meant that Belarus would join the Russian Federation or build a union which is similar to the European Union. However, Belarus refused and status quo was maintained. Despite that, the strategic value of Belarus seemed to continue to rise in Russian eyes because of the international developments. These activities included the United States military activity in the post-Soviet space since the September 11 attacks in 2001, the eastern European states shift towards the west, the plans to deploy NATO's missile defense system in Poland or the Czech Republic, and above all the rise of the colour revolutions. As a result, despite setbacks in political and economic integration, the military-integration processes between the two states continued. As Russia realized that a full integration with Belarus will be costly, it shifted its foreign policy towards a more pragmatic direction. Two major goals were distinguishable in this policy — The first was to reduce the economic burden which Belarus laid on its economy and the second was to take over the energy transit infrastructure in Belarus. These two goals have influenced most of the conflicts and Gas Wars between the two countries.
2010s and Ukrainian crisis
Since 2014, following years of embrace of Russian influence in the country, Lukashenko has pressed a revival of Belarusian identity, following the Russian annexation of Crimea and military intervention in Eastern Ukraine. For the first time, he delivered a speech in Belarusian (rather than Russian, which most people use), in which he said, “We are not Russian — we are Belarusians,” and later encouraged the use of Belarusian. Trade disputes, a border dispute, and a much relaxed official attitude to dissident voices are all part of a weakening of the longtime warm relationship with Russia.
In 1995, the border of Russia with Belarus was destroyed. However, in 2014, the border was restored from the Belarusian side. In turn, Russia in February 2017 created a border zone on the part of the Smolensk oblast. 
Russia accounts for some 48% of Belarus' external trade. Belarus accounts for around 6% of Russia's trade.
Before 2004, Gazprom sold gas to Belarus for Russian domestic prices, mainly due to the political integration process between the two countries. As this process started to falter in the 2000s and late 1990s, Gazprom wanted to ensure reliable transit of Russian gas through Belarusian territory by taking control of the Belarusian transit network. Gazprom tried to purchase the Belarusian network operator Beltransgaz, but disagreements over the price led to the 2004 Russia–Belarus gas dispute, in which Gazprom ceased supplies to Belarus on 1 January 2004. A new gas contract was signed in June, 2004, and relations between the two countries improved afterwards.
In 2009, a serious diplomatic row erupted between the two countries. President of Belarus Alexander Lukashenko accused Russia of offering a $500 million loan on the condition that Belarus recognize Abkhazia and South Ossetia, but added that the position of Belarus was not for sale. Lukashenko has declared that Belarusian citizens must abide by Georgian laws when traveling to the two regions, and the Foreign Ministry has stated that all Belarusian citizens must use points of entry on the Georgian side. Lukashenko declared that instead of Russia, Belarus should "look for happiness in other parts of the planet". Commenting on the close military cooperation between the two countries, Lukashenko likened Belarus' 10 million people as a human shield for Russia against the West, a service that he said "was not free". In July 2009, the so-called Milk War erupted, when Russia banned all dairy imports from Belarus, saying that they did not comply with new regulations. Belarus accused Russia of employing the ban for political reasons, while Russia denied that the ban was political. Russia soon lifted the ban and Belarus resumed deliveries of dairy products to Russia. However, a new dispute arose when Russia claimed that Belarus owed $231 million for gas supplies it had used since the start of the year. Belarus threatened to introduce Border and Customs control on its border with Russia, and refused to attend Collective Security Treaty Organization talks in Moscow. In an interview, President Lukashenko questioned the necessity of diplomatic relations with Russia, since Russia is "blockading" Belarus.
"Russia and Belarus will coordinate efforts to counter attempts to interfere in the internal affairs of the Union State and apply pressure through the introduction of restrictive measures or sanctions."
Russia and Belarus have close military relations and are engaged in various joint military-scientific activities. Russia also operate several military bases and Radars in Belarus which includes the Hantsavichy Radar Station an early warning radar which is run by the Russian Aerospace Defence Forces.
As result of 2014 Ukraine crisis Russia is seeking to replace Ukrainian defense ties with Belarus. On September 14, 2017 Belarusian and Russian relations were back to normal with both conducting military drills.
- Two Decades of the Russian Federation’s Foreign Policy in the Commonwealth of Independent States: The Cases of Belarus and Ukraine Archived 2011-11-20 at the Wayback Machine, Ef.huji.ac.il, p. 17
- Doklad ‘Rossiia-SNG’: nuzhdaetsia li v korrektirovke pozitsiia Zapada? (Moscow: Sluzhba vneshnei razvedki Rossii, 1994)
- “Yeltsin on Protecting CIS Border,” Itar-Tass (22 February 1995), in Russia and the Commonwealth of Independent States: Documents, Data, and Analysis, ed. Zbigniew Brzezinski and Paige Sullivan (New York: Armonk, 1997), p. 311.
- Two Decades of the Russian Federation’s Foreign Policy in the Commonwealth of Independent States: The Cases of Belarus and Ukraine Archived 2011-11-20 at the Wayback Machine, Ef.huji.ac.il, p. 18
- Two Decades of the Russian Federation’s Foreign Policy in the Commonwealth of Independent States: The Cases of Belarus and Ukraine Archived 2011-11-20 at the Wayback Machine, Ef.huji.ac.il, pp. 20-21
- Two Decades of the Russian Federation’s Foreign Policy in the Commonwealth of Independent States: The Cases of Belarus and Ukraine Archived 2011-11-20 at the Wayback Machine, Ef.huji.ac.il, pp. 24-25
- The Strange Death of Russia's Closest Alliance, Global Voices, 21 February 2017
- "NATO Nervous As Russia, Belarus Team Up For Cold-War-Style War Games". NPR.org. Retrieved 2018-11-23.
- "Russia and Belarus launch war games aimed at holding the line against the West". Washington Post. Retrieved 2018-11-23.
- "Россию и Белоруссию разделила зона". Газета.Ru. Retrieved 2018-11-23.
- Oliphant, Roland (2009). "A Problem With the Udder — Belarus and Russia are tumbling into a full-blown trade war that can have only one outcome". Russia Profile. VI (2).
- "Cooperation with Russian Armed Forces | Official Website of Belarus MoD". Mil.by. Retrieved 2016-11-07.
- "Archived copy". Archived from the original on 2014-04-07. Retrieved 2014-10-14.CS1 maint: Archived copy as title (link)
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