Could Bahrain be the next domino to fall? The wave of unrest in the Middle East has spread from Tunisia in North Africa, through to arguably the Arab world's most important state - Egypt - and now on to Bahrain in the Gulf.
While there may be common factors in the unrest, the example of Bahrain also illustrates the strong local factors that colour political developments in each country.
Bahrain as an oil exporter is not a poor country. The unrest there builds upon long-simmering tensions between the Shia majority and a Sunni ruling elite. Modest political reforms have not satisfied the appetite for change.
The exact sectarian division in the country is hard to determine, not least because there has been an active policy of extending citizenship to Sunnis from elsewhere. This too has only served to increase resentment among the Shia majority.
The authorities in Bahrain appear determined to break up the largely peaceful demonstrations with a significant show of force.
This underscores another crucial difference between Bahrain and Egypt. Its small security forces - like many in the Gulf - recruit heavily from other Muslim states like Pakistan and Yemen, so their members are less likely to side with the local population.
Bahrain also has a key strategic role and position. It hosts the headquarters of the US Fifth Fleet. A causeway links it with Saudi Arabia - indeed a province of Saudi Arabia with a significant Shia population of its own.
Not surprising then that events in Bahrain will be being watched in the Saudi capital Riyadh. And so too in Iran which has long had a strategic interest in this crucial island state.
All these factors colour the international diplomatic response and nowhere more so than in London, which still maintains close ties with its former possession.
British Foreign Secretary William Hague has expressed Britain's concerns at the overnight violence to his Bahraini opposite number, Sheikh Khaled bin Ahmad al-Khalifa.
Britain, he said, was stressing the need to uphold "the right to peaceful protest across the region, in Libya and Iran as well as Bahrain".
The US Secretary of State, Hillary Clinton, has also been speaking to the Bahraini foreign minister.
"She expressed her deep concern about recent events and urged restraint moving forward", said a State Department spokesman. "They discussed political and economic reform efforts to respond to the citizens of Bahrain," the US official went on.
Once again the US and European leaders seem to be broadly singing from the same song sheet.
Referring to Bahrain, Mr Hague said it was "time to build bridges between different religious communities".
He noted that the Bahraini authorities had made some reforms in the past and he said that they had "assured the British government that they were sincere about building on these reforms".
Referring to some past comments by Iran concerning its historic claims to Bahrain, Mr Hague also warned against outside interference in the country's affairs. However he did note that there was no evidence of an Iranian hand in the current Shia protests.
It is clear, though, that the events in Tunisia, Bahrain, Egypt and elsewhere are prompting a serious diplomatic rethink in many European capitals.
After all, the events in North Africa and the Middle East are taking place just across the Mediterranean from Europe's shores.
Mr Hague was hosting his Spanish counterpart in London, Trinidad Jimenez. Asked whether the current European ties with the region were sufficient, she said they would have to be looked at.
"These are our neighbours," she said, "and we should help our neighbours."
European policy towards the Middle East runs through a variety of agencies: the EU's Neighbourhood Policy; the almost moribund French-inspired Mediterranean Union; and a variety of bilateral arrangements.
Nobody could perhaps predict this wave of political upheavals. But many analysts now wonder if the arrangements in place are sufficient to prompt a concerted European response to this crisis.