On June 27, 1950, after the outbreak of fighting in Korea, Truman ordered the U.S. Navy's Seventh Fleet into the Taiwan Strait to prevent further conflict between the communist government on the China mainland and the Republic of China (ROC) on Taiwan.
On June 27, 1954, the USSR's Obninsk Nuclear Power Plant, based on what would become the prototype of the RBMK reactor design, became the world's first nuclear power plant to generate electricity for a power grid, producing around 5 megawatts of electric power. the first nuclear reactor that produced electricity industrially, albeit at small scale.
During the previous two years, Nixon had made considerable progress in U.S.-Soviet relations, and he embarked on a second trip to the Soviet Union in 1974. He arrived in Moscow on June 27 to a welcome ceremony, cheering crowds, and a state dinner at the Grand Kremlin Palace that evening. Nixon and Brezhnev met in Yalta, where they discussed a proposed mutual defense pact, détente, and MIRVs. Nixon considered proposing a comprehensive test-ban treaty, but he felt that he would not have time to complete it during his presidency. There were no significant breakthroughs in these negotiations.
On 27 June 1976, Peres, as Minister of Defense, along with Rabin, had to deal with a coordinated act of terrorism when 248 Paris-bound travelers on an Air France plane were taken hostage by pro-Palestinian hijackers and flown to Uganda, Africa, 2,000 miles away.
On 28 June, Iraqi fighter bombers attacked the Iranian town of Sardasht near the border, using chemical mustard gas bombs. While many towns and cities had been bombed before, and troops attacked with gas, this was the first time that the Iraqis had attacked a civilian area with poison gas. One quarter of the town's then population of 20,000 was burned and stricken, and 113 were killed immediately, with many more dying and suffering health effects over the next decades.
According to Jović, on 27 June 1990 he and Veljko Kadijević, the Yugoslav Defense Minister, met and agreed that they should, regarding Croatia and Slovenia, "expel them forcibly from Yugoslavia, by simply drawing borders and declaring that they have brought this upon themselves through their decisions". According to Jović, the next day he obtained the agreement of Milošević.
Despite the confusion and fighting, the YPA nonetheless successfully accomplished much of its military mission. By midnight on 27 June it had captured all of the crossings along the Italian border, all but three crossings on the Austrian border and several of the new crossing points established along Slovenia's border with Croatia.
In the early hours of 27 June the Slovenian leadership was told of the movements of the YPA. The military leadership of the Fifth Military District, which included Slovenia, was in telephone contact with Slovenian president Milan Kučan, telling him that the troops' mission was limited to taking over the border crossings and airport. A meeting of the Slovene presidency was hastily convened at which Kučan and the rest of the members decided on armed resistance.
Further YPA troop movements took place in the early hours of 27 June. A unit of the YPA's 306th Anti-Aircraft Regiment, based in Karlovac, Croatia, crossed the Slovenian border at Metlika.
A few hours later, a column of tanks and armoured personnel carriers of the YPA 1st Armoured Brigade left their barracks at Vrhnika near the Slovenian capital Ljubljana, heading for the airport at Brnik.
The border crossings were a major source of revenue. In addition, by taking control of the borders, the Slovenians were able to establish defensive positions against an expected JLA attack. This meant that the YPA would have to fire the first shot. It was fired on 27 June at 14:30 in Divača by an officer of YPA.
On June 27, 1999, Hawk became the first skateboarder to land a "900", a trick involving the completion of two-and-a-half mid-air revolutions on a skateboard, in which he was successful on his twelfth attempt. After completing the trick, Hawk said "This is the best day of my life."
The criticism attracted by Blatter's refusal to allow goal-line technology or video replays intensified following the controversial Frank Lampard disallowed goal in the match between England and Germany on 27 June 2010.
On June 27, 2017, the company received a record fine of €2.42 billion from the European Union for "promoting its own shopping comparison service at the top of search results."
On 27 June, three BCRC (British Cave Rescue Council) cave divers arrived with specialist equipment including Heyphone LF radios, followed by separate teams of open water divers.