Communist L'Humanité attempts to understand the motivations of the men at the helm in Riyad, presenting a regime torn between oppression and open support for anti-Shia violence.
Catholic La Croix asks why the Saudis are trying to provoke Iran.
And Le Monde warns that relations between the two big regional rivals are now at breaking point.
So, what's really going on?
Nothing simple, that's for sure.
Eastern Saudi Arabia is the centre of the national petroleum industry, the source of virtually all the kingdom's wealth and international prestige. But the largest reserves of crude oil are to be found under two-thirds of the territory where moqt of the Shia minority live.
The 1973 petrol crisis and the 1979 Iranian revolution, which created the first regional Shia government, began to make the authorities in Riyadh worry about this anomaly, and life became increasingly difficult for the oil-region Shia inside Saudi Arabia.
Things have not improved.
Of the 10 terrorist attacks which have hit Saudi Arabia over the past two years, according to L'Humanité, seven have been in Shia areas. Minority communities feel unprotected by the authorities, if not actually targeted.
They claim to be discriminated against in the labour market, qualifying only for menial and dangerous jobs, with no hope of a career in the civil service or the oil industry. Even the army and the police service are effectively closed to Shia applicants. Marriage is forbidden between Sunnis and Shia.
Le Monde notes that the current poor performance of oil on world markets is an additional pressure on Saudi Arabia, with the "proxy war" in Yemen proving long and costly.
Iran blames the Saudis for the collapse of the oil price because they refused to slow production.
Catholic La Croix says the current crisis is a welcome distraction for the rulers in Riyad, who are locked in internal power struggles under an aged and ailing king,
struggling to make ends meet with reduced oil revenues, and unsure what's going to happen regionally, either in Syria or Yemen.
Always assuming that the welcome distraction does not become another major source of trouble, both inside the kingdom and internationally.
La Croix also points to another, more sinister aspect of the toughening of Saudi foreign policy. The Catholic paper says last year's signing of the nuclear deal with Iran is regarded by the Saudi ruling class as a betrayal by the US. In that light, the execution of Nimr al-Nimr could be seen as a sign of determination directed to the predominantly Sunni leadership of the Islamic State jihadi group, a strange contradiction for a state which is, nominally at least, part of the international coalition fighting that very scourge.
On other front pages . . . Libération's main headline reads "Welcome to Europe". They're being ironic, I'm afraid, since the cover picture is a barbed-wire fence, and the story considers a Europe divided on how best to stop the hundreds of thousands of refugees who continue to knock on the door.
Sweden is the latest nation to reinstitute border controls and refuse entry to those without papers.
Libé says there's a sharp east-west divide on the question of whether the refugee problem can best be dealt with at European or individual state level. In the east the countries bearing the brunt of the assault are finding their own solutions in camps, fences and forced expulsions; in the west there's less urgency and a continuing hope for some workable 28-nation deal.
Right-wing Le Figaro accuses French President François Hollande of cheating in order to reduce the unemployment figures.
According to Le Figaro, the government will later this month announce plans to train no fewer than 500,000 people currently on the dole. Whatever the long-term impact of such a plan may be, it will have the immediate effect of knocking half a million names off the top three unemployment categories.
And that, says Le Figaro, with a view to getting Hollande off the hook he baited for himself when he promised not to stand for reelection unless the unemployment figures took a turn for the better.