I don't know what the root of the cause here is. It might be fundamental, that you have leaders who object to demands for elections or something like that, and that France cannot afford to do that and is going to have to tolerate dealing with dictatorships -- I believe that that was a factor in Mali, where the coup leaders had no intention of elections and didn't like being told to hold them. It might be that France doesn't have adequate clout alone. It might be whatever arrangement France is making is otherwise undesirable.

I don't know what the strategic implications for Europe are, but I do wonder. Both Russia and Africa are suppliers of raw resources to Europe. If Russia can collude with other raw resource suppliers, it might be able to place pressure on supplies to Europe.

I know that Nigeria had been looking at an overland pipeline to provide natural gas to Europe, but that needed to pass through Niger. With the coup participants in control of Niger and them aligned with Russia, I'd imagine that Russia might be well-positioned to block creation of that pipeline.

https://en.wikipedia.org/wiki/Trans-Saharan_gas_pipeline

The Trans-Saharan gas pipeline (TSGP; also known as NIGAL pipeline and Trans-African gas pipeline) is a planned natural gas pipeline from Nigeria to Algeria. It is seen as an opportunity to diversify the European Union's gas supplies.

I also don't think that it's viable to just go around Niger. Russia has been involved with a continuous band of countries stretching across the Sahel from the Atlantic to the Red Sea. I don't follow the geopolitics of the Sahel, so I don't know all the factors involved, but if that's not a coincidence, then there's an overland wall across Africa.

Going from west to east, there's Senegal:

https://www.london-globe.com/european-union/2023/12/12/senegal-is-the-next-african-country-in-russias-crosshairs/

Senegal is the next African country in Russia’s crosshairs

Opposition politician Sonko does not hide his ties and sympathies for Russia. . Worrying news for Senegal: the Russians are sending their private armed groups into the country, as they did in Mali and Burkina Faso, in anticipation of the presidential elections.

Mali:

https://en.wikipedia.org/wiki/2021_Malian_coup_d%27%C3%A9tat

Additionally, on 2 June, the African Union suspended Mali, effective immediately until the country could reestablish "normal constitutional order," and urged the military to refrain from interfering with the Malian political process. According to its statement, if Mali did not return power back to civilian leaders, the Peace and Security Council would impose targeted sanctions and other punitive measures. On that same day, France suspended joint operations with the Malian military, as well as national advisory missions. The French Ministry of Armed Forces said that "the decision will be reassessed in the coming days." After consultations with the Malian military and neighboring countries in the Sahel region, France resumed joint military operations and national advisory missions in Mali on 3 July.

On 7 January 2022, Agence France Presse reported that Malian army officials claimed that Russian military advisors had arrived in the country – with about 400 Russian military personnel operating in Sahel state.

Niger:

https://en.wikipedia.org/wiki/2023_Nigerien_coup_d%27%C3%A9tat

On 26 July 2023, a coup d'état occurred in Niger when the country's presidential guard detained President Mohamed Bazoum, and Presidential Guard commander General Abdourahamane Tchiani proclaimed himself the leader of a new military junta, shortly after confirming the coup a success.

At the same time, along with anti-French sentiment, a current of thought favorable to the entry of Russian influence and the Wagner Group mercenary company began to grow. Russia, through Wagner, has been gaining ground at the expense of the French in the region, following the latest coups in Mali and Burkina Faso.

Chad:

https://www.reuters.com/world/africa/putin-meets-chad-junta-leader-russia-competes-with-france-africa-2024-01-24/

Putin meets Chad junta leader as Russia competes with France in Africa

MOSCOW, Jan 24 (Reuters) - Russian President Vladimir Putin on Wednesday met Chadian leader Mahamat Idriss Deby in the Kremlin, courting a country that had previously maintained a pro-Western policy and spurned Russia's recent outreach in Africa's Sahel region.

Russia has been moving to edge out the influence of France, the former colonial power in West Africa and the Sahel, and build ties with countries that have been roiled by a wave of coups since 2020.

And finally, Sudan, and that finishes the span across the continent.

https://en.wikipedia.org/wiki/Russia%E2%80%93Sudan_relations

Sudan has been without a parliament since a popular uprising forced the military overthrow of longtime autocrat Omar al-Bashir in April 2019. The country has been mired in political chaos since an October 2021 military coup derailed its short-lived transition to democracy.

The deal, which surfaced in December 2021, is part of Moscow’s efforts to restore a regular naval presence in various parts of the globe. It was reached during al-Bashir’s reign.

In 2019, Sudan and Russia signed an agreement, which reportedly gives Russian Navy access to Sudanese ports. In November 2020, Vladimir Putin announced that the Russian Navy would proceed with building a base capable of hosting 300 personnel and four warships on Sudan's Red Sea coast. In December 2020, the agreement to build the base was signed, which would give Russia a naval base in Port Sudan for at least 25 years. This was compared to Russia's naval base in Tartus, Syria. However in June 2021, the Associated Press reported that the agreement was not ratified by Sudan's parliament and the Sudanese military indicated it would review the agreement. Sudan’s Chief of General Staff, Gen. Mohammed Othman al-Hussein stated, “We are negotiating a possible review to this deal, to ensure that our interests and our profits are taken into account.”

In February 2023, Russia's foreign minister Sergey Lavrov met Sudanese officials in Khartoum, including the commander-in-chief of Sudanese Armed Forces Abdel Fattah al-Burhan, leader of Rapid Support Forces Mohamed Hamdan Dagalo, and acting foreign minister Ali Al-Sadiq Ali to improve relations amid the International sanctions during the Russo-Ukrainian War, and to conclude a review of an agreement to build a naval base with up to 300 Russian troops in Port Sudan, awaiting ratification from yet-to-be-formed legislative body in Sudan.