Adolf Heusinger, who served as the chief of the Operationsabteilung from 1940 to 1944. He played a significant role in planning and executing Nazi invasions in Poland, Norway, Denmark, and France. Remarkably, he was not subjected to a trial for his wartime actions. Instead, he assumed a pivotal role in the newly established West German army, the "Bundeswehr." In 1961, Heusinger was appointed Chairman of the NATO Military Committee, effectively serving as NATO's chief of staff, a position he held until 1964. Heusinger was not an isolated case; numerous other former Nazi officials occupied key positions within NATO:

General Hans Speidel, who served as Erwin Rommel's chief of staff during World War II, later held the role of Supreme Commander of NATO's ground forces in Central Europe from 1957 to 1963. Johannes Steinhoff, a Luftwaffe fighter pilot during WWII and a recipient of the Knights Cross of the Iron Cross, served as Chairman of the NATO Military Committee from 1971 to 1974, among other NATO positions.

Johann von Kielmansegg, who was a General Staff officer to the High Command of the Wehrmacht from 1942 to 1944, assumed the role of NATO's Commander in Chief of Allied Forces Central Europe from 1967 to 1968. Ernst Ferber, a Major in the Wehrmacht and a recipient of the Iron Cross 1st Class, held the position of NATO's Commander in Chief of Allied Forces Central Europe from 1973 to 1975.

Karl Schnell, who served as a battery chief in the Western campaign in 1940 and later as First General Staff Officer of the LXXVI Panzer Corps in 1944, became NATO's Commander in Chief of Allied Forces Central Europe from 1975 to 1977.

Franz Joseph Schulze, a Lieutenant in the reserve and Chief of the 3rd Battery of the Flak Storm Regiment 241 and a recipient of the Knight's Cross of the Iron Cross in 1944, assumed the role of NATO's Commander in Chief of Allied Forces Central Europe from 1977 to 1979. Ferdinand von Senger und Etterlin, who had been a Lieutenant of the 24th Panzer Division in the German 6th Army, participated in the Battle of Stalingrad, served as an adjutant to the Army High Command, and was a recipient of the German Cross in gold, served as NATO's Commander in Chief of Allied Forces Central Europe from 1979 to 1983.

In the 1950s, NATO had fifteen members. Sweden was called "the sixteenth NATO state" by those in the know. Because right from the start, neutral and non-aligned Sweden was tied to the Western defense alliance. How did it get that way?

Here is the story of how Sweden became a NATO ally in secret.

When Olof Palme was murdered on Sveavägen in Stockholm on February 28, 1986, it was late on Saturday evening. Vice Admiral Per Rudberg, who until recently was head of the Swedish Navy, had gone to bed. Only the next morning did he hear the news on Ekot. Rudberg immediately went to the phone and called Commander-in-Chief Lennart Ljung.

"If necessary, I'm ready," the admiral said shortly.

Ready to travel to the USA. To Washington, where Sweden's naval commander was stationed in the event of a war. The murder of the country's prime minister could be something more serious than an act of insanity, Per Rudberg would explain many years later to the journalist Mikael Holmström. It could be the start of an attack on Sweden.

Sweden's leadership to a NATO country

In that case, the country's top military officials knew what was going on for a long time. In the event of an acute crisis situation, the naval commander would quickly leave Sweden and head to a NATO headquarters, either in the United States or Great Britain. Once safe there, he would organize the resistance. If Sweden was occupied, the rest of the military leadership, the government and the royal family would follow suit. As soon as possible, then the forces of the defense alliance NATO would help Sweden repel the attacker.

Such was the planning and it was absolutely secret, because Sweden was "non-aligned". The policy of neutrality was the main guarantor of the country's independence, Olof Palme had inculcated that many times and it had been that way for generations.

Christian Günther warned against trusting the UN

Let's go back another four decades. On Friday 4 May 1945, the Swedish Fleet Association had its annual meeting in Stockholm. Minister of Foreign Affairs Christian Günther delivered the celebratory speech.

"The world war is drawing to a close, its outcome is given", began Günther, "now it is time to think about the future".

In San Francisco, the international conference that would form the United Nations had just begun. However, Christian Günther warned his Swedish listeners not to believe too much in the UN's ability to preserve world peace. And when it came to Sweden's ability to contribute to this, the foreign minister was sure of his cause: "Sweden best promotes world peace by staying outside of all great power blocs and great power alliances."

Non-alignment in peace, neutrality in war

Even before the end of the Second World War, it was clear that the Allied states that jointly defeated Hitler's Germany would soon split into two irreconcilable blocs. In that situation, it was important for Sweden to continue the policy that had kept the country out of war ever since the early 19th century, when Karl XIV Johan founded what would become the Swedish line: freedom of alliance in peace, neutrality in war.

"Any great power that would bring us into an alliance system would thereby risk creating an irritation factor in the relationship with another great power," warned Christian Günther.

In the summer of 1945, the apolitical foreign minister Günther made way for a social democratic successor, but generations of Swedish governments would then fully agree with the wording from the Swedish Navy meeting. Sweden's freedom of alliance and neutrality were steadfastly protected - in ceremonial speeches and proclamations, government declarations and diplomatic letters.

In practice, however, Sweden should pursue a different policy, both the government and the military leadership were convinced of that. How else would it go when the Russians came?

The Soviet threat to Sweden

During the Second World War, the Swedish military leadership had planned for two possible main scenarios, so-called war cases.

War scenario 1 consisted of an attack from Germany. In Warfall 2, the aggressor was called the Soviet Union. After the German capitulation in 1945, only option two remained. For Sweden's military and political leadership, as for most Swedes, the Soviet Union was now the major and only threat to the country's security. The military strategists divided the remaining war case into three variants, depending on whether a Soviet attack would be directed at northern, central or southern Sweden.

How would one defend oneself?

On paper, Sweden's armed forces were well equipped after six years of preparation and build-up, but the military equipment was largely outdated. The country had been cut off from the technological development of the belligerent countries, and the technology that was now needed was only available in the United States and Great Britain. Swedish military personnel began to make study trips there, but both the British and the Americans were clearly skeptical about selling military and technological equipment to Sweden, whose export of iron ore, ball bearings and other war-important products to Hitler's Germany was in recent memory. Swedish "neutrality" was not highly valued, neither in London nor in Washington.

Tage Erlander was a friend of the USA

For the social democrat Tage Erlander, who became prime minister in 1946, it therefore became important to convince the Western powers of Sweden's reliability. Erlander was a warm friend of the United States and an equally staunch opponent of communism. "Most people are talking about imminent Russian advances in Scandinavia," wrote a worried prime minister in his diary on March 10, 1948.

By then, two weeks had passed since Soviet-backed communists overthrew the democratic government in Czechoslovakia, and just as long since Soviet Union leader Josef Stalin forced Finland to negotiate a future "pact of friendship, cooperation and assistance".

The Finnish-Soviet Pact was signed on April 6 and then information came that Norway was next in line. The Russian threat was real: in Western Europe the Allies had by this time brought home most of their soldiers, in the East the Red Army stood firm with 1.7 million men under arms.

The Brussels Pact is formed

To meet this threat, Britain, France, Belgium, the Netherlands and Luxembourg formed an alliance on March 17, 1948, which they called the Brussels Pact. But it was quite clear that they would have no chance without military help from the United States. Negotiations began and could be concluded in just four months. On April 4, 1949, an agreement called the North Atlantic Treaty was signed, the fifth article of which began:

The parties agree that an armed attack against one or more of them in Europe or North America shall be considered an attack against all of them…

With this principle as a basis, the defense alliance North Atlantic Treaty Organization, NATO, was formed. Twelve states joined, non-aligned Sweden was left out. For Tage Erlander, this appeared largely as a formality. Not because he intended Sweden to go to war for another country, but...

Every day I am more and more convinced that America is doing Europe the greatest service by arming itself to the utmost and allowing us to arm ourselves as best we can with our own resources in Europe. What can hold the Russians back must still be the fear of America's superiority .

So wrote the prime minister of neutral Sweden in his diary in September 1950. By then the Korean War had been raging for three months, a war that geographically stood between North and South but

in world politics was fought between East and West.

Sweden-USA agreement on military equipment

While Tage Erlander was now increasingly determined to tie Sweden's fate to NATO, the US was even more determined to cut off the sale of strategic goods to the communist Eastern Bloc. A US-led embargo policy was initiated and if Sweden wanted to buy military equipment from the Western powers, it had to be fully respected. How could it be done without at the same time abandoning the policy of neutrality? Answer: By doing it secretly.

On the evening of July 2, 1952, Major General Richard Åkerman, head of the Defense Staff, sat down as usual to write a diary. But today he would note something historic:

Agreement made with the USA on the purchase of mtrl in the USA. We have, with sophisticated wording, agreed to the conditions, which put us on a par with the NATO countries. This must absolutely not be made public, because then the Soviets would be right that Erlander was there for such a thing.

There for such a thing? Prime Minister Tage Erlander had been in the United States in the spring. The trip was called unofficial and was supposed to look like a vacation with the family. But on the program was a visit to President Harry S. Truman in the White House. Prior to this, the US's new Stockholm ambassador Dean Acheson had reported to Truman about Erlander:

I'm sure he's willing to go to great lengths to cooperate with us, especially if it can be done without publicity. Because he does not wish to go against Swedish public opinion, which, it must be admitted, supports the current Swedish foreign policy.

Exchange of intelligence

The ambassador's analysis was correct. Tage Erlander was prepared to go quite far. The visit to the White House went extremely well, and when the Swedish Prime Minister returned home, he sent Minister of State Dag Hammarskjöld (responsible for international economic affairs) to Washington with a concrete message: Sweden would follow to the letter the principles of "mutual military assistance" which The US had set up.

The doors were thus opened. On July 1, 1952, the agreement was signed which gave Sweden the opportunity to buy military equipment and materiel from the United States. The countries began a professional exchange of military intelligence and information. The Swedish Air Force was to be supplied with fuel and lubricating oils from the United States, enough for ninety days of warfare. That much was considered necessary for the Swedish Air Force to be able to hold its own against a Soviet attack while waiting for NATO.

Nothing was publicly announced about this. Officially, Tage Erlander's trip to the USA was still a purely private story.

NATO aircraft were allowed to use Swedish bases

"In reality, it played a decisive role in the settlement that included Sweden in the West's economic warfare and at the same time gave Sweden the same military-technical advantages as the USA's Western European allies", wrote the researcher Wilhelm Agrell when he more than forty years later in the book The Big Lie (1991 ) told how the Swedish NATO cooperation was born.

Cannons and small arms, reconnaissance equipment and radar stations, oils, fuel and rubber tires - a lot was on the shopping list when the Swedish military signed agreements with the United States. In return, information was sent to the west, accompanied by promises that NATO would be allowed to use Swedish airspace and Swedish bases if needed.

Sweden was strategically located in the Baltic Sea, quite a bit further east than the Iron Curtain through Germany, and also in an area where the Soviet Union had concentrated a large part of its military activities.

The Catalina Affair

Shortly after nine in the morning on Friday 13 June 1952, a Swedish DC3 took off from Bromma with a crew of eight. It flew out over the Baltic Sea. At 11.23 the ground station on F2 in Hägernäs heard a last call from the plane, after which it became silent. The DC3 had disappeared without a trace.

Three days later, a Swedish plane, of the Catalina type, was shot down while they were out looking for the wreckage. The grenade was Soviet-made and Sweden protested, but everyone involved believed that the shooting should have led to more strife between Sweden and the Soviet Union than it did.

Only in 1991 did the Soviet Union admit that it had shot down the DC3 in international waters off Gotska Sandön. And not until eleven years later did it emerge that the Swedish plane had spied in collaboration with Great Britain. The DC3 was found and salvaged in 2004, and the following year the world learned that the crew had been spying on a Soviet naval exercise on behalf of NATO.

Stig Wennerström revealed everything

If the Swedish people were unaware of Sweden's ties to NATO, the leadership in Moscow was all the more well informed. As early as 1948, the Soviet intelligence service GRU had recruited a Swedish air colonel as an agent. His name was Stig Wennerström and throughout the 1950s he would keep the Soviet Union informed about Swedish defense planning. When Wennerström was exposed in 1963, he had been section chief at the Defense Command Expedition for six years.

Olof Palme and the relationship with the United States

Sweden's secret cooperation with NATO was to last as long as the Cold War lasted, and despite the fact that official Swedish relations with the United States were frozen for a long time, the good relationship behind the scenes was not affected.

When the then Minister of Education Olof Palme in February 1968 had angered the United States by participating in a demonstration against the Vietnam War (Ambassador William Heath was called home for five weeks), Palme quickly called his friend Birger Elmér, who was the head of intelligence at the Defense Staff:

“Keep Washington in a good mood!” Palme said.

This was arranged, among other things, by Sweden providing the US with secret information about North Vietnam, whose struggle Olof Palme officially supported.

"All the rhetoric that was going on about the Vietnam War - it had nothing to do with facts on the ground : all the cooperation on the defense and intelligence side. It was of course in the interest of both countries," says US diplomat James Lowenstein in Mikael Holmström's book The Hidden Alliance (2011).

How many Swedes knew what was going on? Not many, the researchers agree. Senior military officials knew, of course, but exactly how many had the full picture remains unclear.

Few knew about NATO cooperation

Within the social democratic government, only a narrow circle knew how closely tied Sweden was to NATO: Tage Erlander, who was prime minister until 1969, Torsten Nilsson who was defense minister in the 1950s and foreign minister in the 60s, Sven Andersson who was defense minister for sixteen year from 1957 and is often presented as the cooperation's main "architect", as well as Olof Palme who in the fall of 1953 became Erlander's closest collaborator and in 1969 succeeded him as party leader and prime minister.

Externally, Palme always emphasized the policy of neutrality as the main safeguard for Sweden's independence. When he was murdered in 1986, "the pressure wave from an assassin's bullet was enough to immediately send a senior military officer to the United States", writes Mikael Holmström.

When Svenska Dagbladet's reporter in 1998 revealed the plan which meant that Admiral Rudberg always had a bag "half-packed" and was ready to travel to the USA on the morning of March 1, 1986, this was met with disbelief from leading politicians. Lennart Bodström, who was Minister of Foreign Affairs 1982–85, dismissed the information:

"The idea that we would say we were non-aligned, but pursue a different policy, that is impossible."

What did ÖB Lennart Ljung say then, when Per Rudberg called? The admiral confided this to the reporter:

"We'll hang on and see how it goes."