The Gulf state is daring to flex its diplomatic, cultural and military muscles. And the effects are being felt from the Shard to Syria

On Thursday evening Sheikh Hamad bin Jassim al-Thani, who combines the roles of Qatar's prime minister and foreign minister, stood with the Duke of York and mayor of London, Boris Johnson, to watch the inauguration of the Shard. As blue and green lasers, accompanied by the London Philharmonic Orchestra, lit up a London skyline now dominated by the 310m skyscraper, the performance was streamed live around the world.

If the opening of western Europe's tallest building – presided over by Hamad, whose country's sovereign wealth fund owns 95% of the development – was a demonstration of Qatar's rapidly growing global visibility and influence, a few days before, in an equally vast but older building, that influence was being exercised far more discreetly. The building was the UN's Palais des Nations in Geneva, where last Saturday Hamad met the US secretary of state, Hillary Clinton, and other foreign ministers to press his country's case for firmer international action over Syria.

Both scenes underline a phenomenon: the emergence on to the world stage as a considerable diplomatic, cultural and even military player of a tiny state whose huge ambitions to spread influence around the globe are fuelled by enormous wealth and devotion to a strict interpretation of the Qur'an. That ambition is being realised, from the sports stadiums and skyscraper penthouses of western capitals to the industrial centres of China and the battlefields of Syria and Libya.

A generation ago Qatar – whose people are the world's wealthiest by virtue of its oil and natural gas reserves – barely registered on the global radar. It is a former British protectorate ruled by the al-Thani family since the 19th century; its present emir, Sheikh Hamad bin Khalifa al-Thani, seized power in 1995 from his father in a bloodless palace coup. Today it is difficult to avoid its money and influence.

In London, the al-Thanis' investment arm, Qatar Holdings and the Qatar Investment Authority, have been on a long shopping spree, spending more than £13bn in recent years on purchasing Chelsea Barracks, Harrods and the Olympic Village. Qatar is the largest shareholder in Barclays Bank. Its global investment strategy most recently has seen the statelet aggressively pursue new openings in China.

The Qatar Foundation sponsors Barcelona football club, a reminder that in 10 years' time it will play host to the World Cup. Then there is the Doha-based al-Jazeera television, considered the most important Arab news TV channel, owned by Qatar through the Qatar Media Corporation – which last week claimed that it had evidence that the late Palestinian leader Yasser Arafat was poisoned with polonium.

The emirate also hosts the Taliban and Hamas regional offices, as well as a host of international organisations – Georgetown University, the British Royal United Services Institute for Defence and Security Studies – creating a space where the west rubs shoulders with the Islamic world. Indeed, until 2009 Qatar even hosted an Israeli trade centre, which closed its doors after the Israeli incursion into Gaza.

Since the Arab spring, Qatar has attempted to position itself at the forefront of the transformation of the region, giving military support to the opposition to Colonel Muammar Gaddafi in Libya as well as backing key players in the country's fractured post-revolutionary politics through tactics – some diplomats have alleged – that have included weapons shipments.

More recently, it has been accused of funnelling arms to Syria's opposition groups – a claim the prime minister denies, despite the fact that Qatar vocally supports the arming of that country's opposition.

All of which leads to questions: what does Qatar want from a foreign policy that combines the deployment of both soft and – increasingly – hard power, and how did such a small country get to be so important?

That – as the Economist pointed out last year in a profile of "the pygmy with the punch of a giant" – was precisely the question that was asked by Egypt's former autocrat, Hosni Mubarak, when he paid a visit to al-Jazeera's headquarters in Doha in 2001. He reportedly grumbled: "All that noise from this little matchbox?"

It is a question that has been framed in so many words by everyone from Arab leaders to western diplomats struggling to understand not only the complex combination of considerations driving Qatari foreign policy but also its trajectory.

In some respects, say analysts who have studied that policy, the diplomacy of the al-Thani family is interpreted through the very personal filter of the emir, his prime minister and Sandhurst-educated crown prince Tamim, the head of its tiny military.

With a population of fewer than two million – of whom fewer than one in seven is native-born – Qatar sits on a flat peninsula that juts out from the coastline of Saudi Arabia, facing Iran across the Gulf. When it ceased being a British protectorate in 1971 it elected not to join the United Emirates.

While Qatar was a founding member of the Gulf Co-operation Council in 1981, which guarantees its sovereignty, its foreign policy has long been focused on forging friendships and alliances to guarantee its independence and security, not least through its hosting of US Central Command since 2002.

"You only have to look at Qatar's location on the map to see that it is in a rather heavy neighbourhood," says Jane Kinninmont, a Gulf expert at the Chatham House thinktank. "There is a feeling that it needs a lot of allies. So Qatar pursues alliances both with larger countries and smaller ones that it can rely on in places like the UN general assembly."

It is precisely this, believes Shadi Hamid, director of research at the Brookings Doha Centre, that has driven a "creative" foreign policy that has long required Qatar to cultivate friendships.

That, however, is not enough to explain Qatar's emergence as an international player punching far above its weight. Instead, the reality is that it has benefited from a complex combination of events bound together by the powerful personalities of the emir and his prime minister built on the foundation that Qatar should "matter".

It is precisely over this issue of self-validation that the dots between the Shard and the Olympic village and Qatar's increasingly assertive diplomacy are joined.

"Fifteen years ago no one had really heard of Qatar," says Kinninmont. "Now we know about it not only because of its trophy investments in places like London but because of its foreign policies. It is very brand-conscious and in part that is because it seeks to define and brand itself through what it is involved in." That is as applicable to notable buildings as its support for revolution in the Arab world. Qatar's strategy was for a long time similar to that of Turkey's, a "zero problems" foreign policy that focused on increasing its influence by acting as both a crisis mediator and through winning friends. But in the middle of the Arab spring, which saw other leaders forced to look inwards, Qatar, with its relative stability, seized its opportunity to take on a more active role.

Speaking three years ago, Qatar's prime minister insisted: "Our sources of power are our belief in God, our self-confidence and the emir's clear perception, in which there is no competition with anyone. We want to compete with no one. Our country is small and I repeat this a hundred times."

While few would argue with Qatar's declaration of "self-confidence", it is the last statement that many are increasingly sceptical about, not least since March last year when the emirate dispatched six Mirage jets to join Nato operations over Libya and military advisers and anti-tank missiles to the rebels.

It was this moment, as David Roberts, deputy director of the Royal United Services Institute, argued in a piece for Foreign Affairs last year, that marked the "qualitative change" in Qatar's foreign policy from an "activist" but militarily "unthreatening" stance to active intervention.

Roberts's explanation for the emergence of Qatar as a key regional actor is intriguing. He argues that, following his coup in 1995, the emir was anxious to develop "a positive and liberal image ... with a single goal – to consolidate his regime in a hostile environment where supporters of the old regime inside the ruling family and outside the monarchy [Saudi Arabia] cherished hopes for restoration."

It was a policy that a year later would see the launch of al-Jazeera.

It has been more recent events, however, that have defined Qatar. Despite being an absolute monarchy – although it will hold elections next year for a royal advisory body – the state has seen no contradiction in throwing its weight behind popular movements fighting long-standing autocrats, a position viewed by some in the region with deep scepticism.

"The Arab spring changed everything," says Hamid. "Among Arab leaders, Qatar was the only one that was ahead of the curve in the Arab spring and willing to take risks."

Ironically, he argues, it was the small and wealthy population and the lack of pressure for democracy, that allowed it to feel less "existentially" challenged by what was happening around it than its bigger neighbours, not least Saudi Arabia and Iran.

"It saw what was happening," says Kinninmont, "and has been aligning itself with the Muslim Brotherhood and brotherhood-based movements everywhere. It has sided with what it sees as the rising trend." That support for parties with their roots in the brotherhood – including Tunisia's Ennahda party, whose recent victory Qatar financed, comes despite the fact that the emirate itself embraces the Wahhabi tradition of Islam and has also hosted radicals from that school. This has led to suspicions in some parts that its agenda is religiously driven, although others argue that it is less ideological and more opportunistic. But if Qatar has long learned to be pragmatic – managing to host a huge American base while still conducting military exercises with its neighbour, Iran – its approach, says Kinninmont, has also been driven by very personal factors, not least in the friction with Syria's president, Bashar al-Assad. "The emir spent a lot of time cultivating Assad as an ally. The feeling was that they could explain and he would listen. But Assad didn't want to listen."

The change of tack in Qatar's policy from acting as mediator in a series of crises, including between Yemen's government and Houthi rebels and in Darfur, to a more interventionist stance has not been without its risks.

In the immediate aftermath of the revolution in Libya, western diplomats in Tripoli complained bitterly about Qatari interference. Qatar's activism on behalf of Syria's opposition and the suspicion that it has been involved in channelling arms to its members has drawn criticism both public and private.

It has led some to speculate that Qatar will not be able to sustain its influence. It has been remarked that, while it has benefited from the distraction of neighbours like Saudi Arabia at the start of the Arab spring, the long-term consequence of Qatar's actions in the last year and a half – not least its support for Sunni Islamist movements – may be drawing it closer to Riyadh in the increasingly apparent sectarian divisions thrown up by the Arab spring, not least the conflict in Syria.

Equally challenging for Qatar is that its newly assertive policies may be in danger of undermining the careful network of friendships it has worked so long and hard to develop, making new enemies.

Even among Libya's revolutionaries who benefited from Qatari military assistance there has been grumbling. Among those who have spoken out is General Khalifa Hiftar, who while welcoming Qatari "aid [that] comes through the front door… if it comes through the window to certain people [and] bypassing official channels, we don't want Qatar".

Hamid admits: "Everything comes at a price. Opposition to Qatar has risen. There is the risk of blowback for the emirate. But they know that that goes with the territory."

Then small Qatar might well discover, as others have before, that the realities of hard power trump the expensive and subtle business of soft power – laser light shows and gleaming towers included.