Yesterday, May 27, Henry Kissinger celebrated his 100th birthday. Yet, Kissinger remains an enigma despite being one of the most visible persons of the past century – a century he played no small part in shaping.

After arriving in the US in 1938 to avoid the Nazi persecution of the Jews, Kissinger studied at Harvard and embarked on an academic career that led him to advise various US administrations, including those led by Dwight Eisenhower, John F. Kennedy and Lyndon Johnson.

Kissinger advocated realism, where states remain the most critical actors in a vastly anarchic international system. All states are concerned with their security and pursuing their self-interest. Given this, states are responsible for constructing harmonious relations through which they can interact without damaging such interests.

He developed approaches which allowed the US to navigate the dangerous and highly charged waters of the Cold War. For example, he sought to move the US to adopt a ‘flexible response’ to the Soviet Union involving tactical nuclear weapons, conventional forces and technology based on the US’ strategic requirements.

Kissinger’s influence in the corridors of power was cemented in December 1968 when he was appointed president Nixon’s assistant for national security affairs. Eventually, he headed the national security council (1969 – 1975) and was secretary of state between September 1973 and January 1977.

Three policies are the hallmark of Kissinger, namely, the end of the Vietnam War, the opening to China and détente. Each has shaped the 20th and the 21st century.

Vietnam is arguably the most controversial of Kissinger’s policies. He initially adopted a hard-line policy culminating in the controversial and bloody US bombing of Cambodia. Later, however, he embarked on a policy of disengagement of the US from Southern Vietnam and its replacement by South Vietnamese forces.

Finally, after prolonged peace negotiations, a ceasefire agreement was signed in Paris on January 23, 1973. As a result, US troops withdrew from Vietnam, leaving South Vietnam to fend for itself and, eventually, capitulate.

In his masterpiece Diplomacy, Kissinger argues that the Nixon administration wanted “to get beyond Vietnam without suffering geopolitical losses”. The withdrawal ushered in a period of détente. This was not without its critics: “Liberal critics treated it as an end in itself while conservatives and neo-conservatives rejected the geopolitical approach as so much historical pessimism, preferring a policy of unremitting ideological confrontation.”

Reflecting on this period in the autobiographical White House Years, Kissinger argues that détente “did not prevent resistance to Soviet expansion” but “fostered the only psychologically possible framework for such resistance”. He built no illusions for himself; he knew the US and the USSR were ideological rivals and détente could not change this. However, “the nuclear age compels us to coexist”. He adds: “Rhetorical crusades cannot change that either.”

Kissinger was responsible for a greater opening to the People’s Republic of China. Initially, the USSR relied on Beijing’s passivity or support for its stances. However, Beijing grew distrustful of Soviet power. The international diplomatic game played by Kissinger became more complex since it sought to play one side against the other. Yet, at the same time, it also made détente more necessary.

Henry Kissinger remains an enigma despite being one of the most visible persons of the past century- André DeBattista

He travelled secretly to Beijing. The state department and the defence department were unaware of these dealings lest such initiatives be derailed. Ultimately, this backroom diplomacy made Nixon’s visit to China possible in February 1972. In his book On China,  Kissinger gives his view of this event: “The American motive for the opening was to put before our people a vision of peace transcending the travail of the Vietnam War and the ominous vistas of the Cold War. China, though technically an ally of the Soviet Union, was in quest of manoeuvring room to resist a threatened attack from Moscow.”

Once again, there is no mistaking his realism. Yet, he is also careful to ensure that this same realism does not translate into blind exceptionalism. He tries to understand China and explain the Middle Kingdom to a lay audience.

He argues that no country equals China “in persisting – and persuading its neighbours to acquiesce – in such an elevated conception of its world role for so long, and in the face of so many historical vicissitudes”. To understand China’s posturing, he posits that one must begin by understanding and appreciating the traditional context – “even at the cost of some potential oversimplification”.

These short vignettes from his long and distinguished career can help us understand why Kissinger remains so controversial and difficult to understand. He believes the ends justify the means. Yet, unlike many contemporaries, an end goal can be discerned. He combines vision with pragmatism, realism with dangerous ruthlessness.

He has a thorough understanding of leadership which he outlined in a recent book – written aged 98 – on leadership.

Firstly, he believes leaders think and act at the intersection of two axes – “between the past and the future… Between the abiding values and aspirations of those they lead”. Their challenge is to assess realistically their society based on “its history, mores and capacities”. What they know must be balanced with “what they intuit about the future”, which is always uncertain and unknown.

Secondly, he believes leaders are not mere strategists but must also be educators: “communicating objectives, assuaging doubts and rallying support.”

Thus, the leader also needs “the qualities of the artist who senses how to sculpt the future using the materials available in the present”.

Thirdly, he places emphasis on instinct – informed historical intuition – which is, perhaps, what shaped his decision-making process most: “Meaningful political choices rarely involve a single variable; wise decisions require a composite of political, economic, geographical, technological and psychological insights, all informed by an instinct for history.”

Against this, it must be said that, while instinct is vital, it also means that, sometimes – all too often – it tends to play Russian roulette with people’s lives. This, perhaps, is also the tragedy of Kissinger.

He is undoubtedly a profoundly transformative leader with a refined intellect, though some may legitimately question whether these transformations lacked the humanity that politics needs.