The government hoped North Korea would fail to qualify for the 1966 World Cup finals as they believed the state's presence in the competition could cause political "headaches", documents today revealed.
Previously secret records released by the National Archives shed light on the fraught exchanges between government officials over the possibility of North Korea attending the finals.
The Foreign Office even considered refusing to grant visas to the North Koreans as a way to solve the diplomatic problem.
England, hosts of the 1966 competition, did not at the time, officially recognise North Korea, which referred to itself as "The Democratic People's Republic of Korea".
Officials worried that allowing the country to attend would cause diplomatic shockwaves, particularly with anti-communist South Korea.
Korea was divided into Soviet and American occupied zones in 1945.
Five years later, with massive Soviet assistance, the North embarked on a three-year war with South Korea.
The conflict drew in countries such as the US, the UK and China and cost hundreds of thousands of lives.
With the Vietnam War looming and the Cold War in full swing, the relationship between North and South Korea and its ramifications for the rest of the world, was seen as a potential political tinderbox.
A Foreign Office memo written in the months before the World Cup read: "The simplest way to solve the problem might be to refuse visas to the North Korean team.
"But if we do this the consequences could be very serious. Apparently FIFA has made it very plain to the FA that if any team has won its way through to the finals is denied visas then the finals will take place elsewhere.
"This would be a disaster for the FA. You can imagine what the papers would make of this.
"We would be accused of dragging politics into sport, sabotaging British interests and so on."
The Foreign Office also envisaged problems arising if it imposed restrictions on the North Koreans during the tournament.
Another memo explained: "The North Koreans will probably object very strongly if they are prevented from playing their National anthem, displaying their national flag etc, when the other 15 countries taking part in the finals are all permitted to do so."
Officials were also concerned that flying the North Korean flag and playing its national anthem could affect sporting rules in place on East Germany, which was seen as a Soviet puppet.
Another memo revealed: "We would prefer as few manifestations as possible of North Korean "nationality" both because we must avoid any implication that we have recognised North Korea and because anything the North Koreans are allowed to do in Britain will be used as a precedent in the future for the much more tricky case of the East Germans."
The FA warned the government that losing out on the finals by banning North Korea would come at a financial cost to them and the clubs hosting the competition.
An FA letter warns: "We must not risk the possibility of these Championships being taken away from this country after we have spent some four years in preparation and, of course, involved ourselves in a very considerable financial outlay."
After much official head-scratching it was decided to allow the North Korean flag to be flown at all matches alongside the flags of other competitors.
But national anthems would only be played for the two teams playing in the opening game and the two teams contesting the final.
The government insisted that the state be referred to as North Korea and not the Democratic People's Republic of Korea.
Despite predictions of failure, North Korea made it through to the quarter finals of the competition, beating much-fancied Italy along the way.
But England had the last laugh, running out as eventual winners of the tournament.
North Korea have once again made this year's finals in South Africa, as have bitter rivals South Korea.