In the wake of the Tunisian revolution in 2011 I spent some time in the country's capital, waiting to cross the border into neighbouring Libya as the Arab Spring reached its climax there.
Walking along the wide boulevards that dissect Tunis you could be forgiven for thinking at times you were in Paris. Hardly surprising, given Tunisia's time under French occupation before it gained independence in 1956.
What struck me most about Tunis, though, was the apparent ease with which the devout and the secular appear to sit cheek-by-jowl.
In many ways it was tailor-made for its role as the cradle of the Arab Spring when, a little over two years ago, a young fruit seller named Mohammad Bouazizi set himself alight in protest, sparking a revolution in his country that went on to reverberate around the Arab world.
As one of the most progressive countries in the region there were high hopes for the gains made in the wake of Tunisia's revolution.
Over the last few days, however, the killing of the country's left-wing opposition leader, Chokri Belaid, has thrown the spotlight on the growing divide between secular and Islamist factions.
Outspoken against Ennahda, the Islamist party that heads the country's government, Mr Belaid was not short of enemies. Shot in the head and neck outside his home, his killing marks the first political assassination since the Arab Spring uprising in 2011 and has dangerously stirred the already bad blood between Islamists and more secular-leaning Tunisians.
Reacting immediately to the assassination of Mr Belaid, Tunisia's Prime Minister Hamdi Jebali – himself a member of Ennahda – announced his intention to replace the government led by his moderate Islamist party with a non-partisan cabinet until elections can be held.
Yesterday, however, Ennahda effectively disowned the Prime Minister, insisting he "did not ask the opinion of his party".
The resulting fallout has left Tunisia on a political knife edge.
What the country now faces is not only a dangerous divide between secularists and Islamists, but a ruling Islamist party itself riven with differences – in part a result of Mr Jebali's handling of the crisis.
In a nutshell, Mr Belaid's assassination has laid bare the growing threats to stability in Tunisia.
Many regional security analysts contend these threats are primarily a result of the increasing influence of Salafist militants both inside Tunisia and across the region as a whole.
Since the revolution that led to the fall of former Tunisian President Zine El Abidine Ben Ali, the Salafists have become increasingly active, staging protests against Ennahda who, despite being Islamist, they regard as too accommodating towards political opposition within the country.
Faced with this, Ennahda has had the tricky task of trying to juggle its efforts to incorporate some of the more mainstream Salafists to help quell protests, while at the same time working to appease secularist suspicious of the party's "collaboration" with Salafists.
Despite Ennahda's efforts to keep them at bay, hardline Salafist vigilante groups –"committees to defend the revolution" – have begun taking over local districts, adopting violent tactics that have led to the breaking up of trade union rallies and attacking shrines they deem to be idolatrous.
All this of course is aimed at retaliation and destabilising the Tunisian government. To that end this week's assassination may well have been the work of Salafist jihadists attempting to push things over the precipice for Ennahda.
As recent events in north and west Africa – notably Libya, Algeria and Mali – have shown, jihadist fighters and weapons have flowed across this region.
Tunisia is not known for having the most stable internal security apparatus and, like its neighbours, has struggled to control its borders and southern desert areas.
Given this, it's more than likely jihadists have penetrated Tunisia with the aim of helping to further the Salafist cause and create instability in the country.
But there are other threats over and above secularist-Islamist issues that could contribute to destabilising Tunisia. Some have distinct parallels with what is happening in Egypt.
Just as in Egypt, Tunisia's Islamist-led government has faced increasing economic and social pressures as this popularly elected transitional government has struggled to address the problems it inherited after Ben Ali's fall. Unlike Egypt, though, Tunisia's Ennahda has failed to form a consolidated working partnership with key state institutions or members of the previous regime, as Egypt's Muslim Brotherhood has managed with the Egyptian military.
Empowered by popular support during the Arab Spring, both Tunisia and Egypt's Islamist governments and movements have found their transition from the role of opposition parties to that of governance difficult to say the least.
In Tunisia's case, Mr Belaid's assassination and the rapid spread and popular acceptance of rumours of Ennahda's culpability are signs of the deep mistrust and frustration with which many Tunisians view their own government.
As the first state to experience the mass public uprisings that shook the Middle East and North Africa in 2011, Tunisia has served as a case study for the challenges of inexperienced Islamist parties transitioning into ruling states beset by structural, economic, social and security problems.
Yesterday the protesters were again on the streets of Tunis and other cities. Labour union leaders meanwhile have declared a general strike for today in protest at Mr Belaid's assassination.
For some time now Tunisia's Jasmine Revolution has looked jaded. Now many Tunisians are fearful it is in danger of being hijacked by radical Salafi Islamists and that Ennahda is coming increasingly under their sway.
It is imperative the Tunisian government moves fast to dispel suspicions it is lenient towards the Salafist militants.
"The revolution at the beginning was a fight for dignity and freedom, but violence is taking over," warned French Foreign Minister Laurent Fabius yesterday.
The boulevards of Tunis will most likely be a volatile place in the days ahead.