Yesterday, France announced that it had invoked the EU’s collective defense clause in response to Friday’s terrorist attacks. This was the first time an EU member has invoked Article 42.7 of the Lisbon Treaty, which states that EU countries have “an obligation of aid and assistance by all the means in their power” to any fellow member that is the victim of an armed attack.

Importantly, France chose not to invoke Article 5 of the North Atlantic Treaty, which obligates each NATO member to take “such action as it deems necessary, including the use of armed force, to restore and maintain the security of the North Atlantic area” if another NATO member is attacked. Article 5 also has been invoked only once, when the United States did so after September 11.

It is not entirely clear why France made this particular decision, which for reasons I will set out below may have important long-term consequences that the French leadership hasn’t anticipated.

It may be that Paris’s decision was made in collaboration with the White House. Both governments may have reasoned that invoking Article 5 would require NATO to get involved militarily in Syria and Iraq at a time when NATO is already hard pressed to build up its eastern flank defenses. They may also have worried that NATO participation in the anti-ISIS campaign would undermine the already precarious unity of the current coalition.

That said, it is also possible that Paris made the decision on its own, and that it did so because it wanted to signal Moscow that it intends, regardless of Washington’s preferences, to take Putin up on his offer to enter into a broad coalition against “terrorism” in general and ISIS in particular. French President François Hollande’s reasoning may be very straightforward: ISIS is a much bigger threat to France than Russia, and the West and Russia need to cooperate militarily to defeat their common enemy. Bringing NATO into the equation would make cooperation with Russia much less likely, so no Article 5.

It is also possible that Friday’s terrorist attacks have led Paris to conclude that it is not just cooperation with Russia in the fight against ISIS that is needed. It may also have decided that there is a need to reduce political and military tensions with Russia generally, regardless of whether Washington or other European governments agree. If so, Paris may follow up by openly advocating political normalization with Moscow and the easing or elimination of Western economic sanctions.

Paris’s objectives will doubtless become clearer in the days ahead, but one thing can be said with confidence at this point, which is that the latter interpretation – that Paris is going to use military cooperation with Russia in Syria to normalize political and economic relations with Moscow – is what the Kremlin is hoping for.

Regardless, Russia has a critical decision to make in responding to Hollande’s overtures: should it try to use its military involvement in Syria to reduce tensions with the West as a whole, or should it use it to drive a wedge between the United States and France, and possibly between Paris and Berlin as well. (For a thought-provoking essay on the implications of the Paris bombings for relations between France and Germany, see James Poulos’s essay in Foreign Policy here.)

So far my sense is that the Kremlin is taking the latter course, although it is still early days.

Moscow confirmed yesterday that the Russian airliner that crashed last month was brought down by a bomb, after which Putin made a television appearance in which he promised to hunt down the perpetrators. He was also shown meeting with his top commanders to discuss military operations in Syria, during which he ordered the captain of a Russian missile cruiser to approach a French naval force in the eastern Mediterranean and cooperate with it in Syria. As he put it, “You need to establish direct contact with them and work together as allies.” Putin and Hollande also spoke by phone, and according to the Kremlin’s official website they agreed “to ensure closer contacts and coordination between the two countries’ military agencies and special services in the course of anti-terrorist operations conducted by Russia and France in Syria.”

Putin’s use of the term “allies” during the meeting with his military commanders was almost certainly deliberate. Moreover, note that the reference was to France specifically, with no mention of the United States or the coalition of which France is a member. Also yesterday, Russia’s foreign minister, Sergei Lavrov, claimed that U.S. airstrikes over the past year had avoided hitting those ISIS units that posed the greatest threat to the regime, the implication being that Washington was using ISIS to bring down Assad.

So France should be treated as “an ally” but the United States should not be (to understate the case).

At any rate, I doubt that the Kremlin is trying to use its Syria intervention to improve relations with the United States or the West as a whole. Rather, I suspect that its primary goal is to divide the West, the assumption being that a divided West will limit NATO’s growing military presence along Russia’s western borders.

For reasons I’ve laid out in earlier posts, I doubt that particular objective is going to be realized – that is, I don’t think dividing the west will help very much with Russia’s immediate security problems, which are driven primarily by growing fears of Russian military aggression among Russia’s neighbors. And I doubt NATO and U.S. assistance to those countries is going to change as a result of developments in Syria.

On the other hand, Moscow’s policies have already contributed significantly to the European Union’s mounting political problems, and that is not going to change. But it has not been very successful, at least to date, in dividing the United States from its key European allies on security issues or on the Western response to Russia’s actions in Ukraine.

That may now change, depending on how the Syria/ISIS drama plays out, particularly if Paris decides that it cares less about Atlantic or EU solidarity than it does about combatting ISIS with Russian help.

A final point about France’s decision to invoke the EU’s collective security commitment that I doubt Paris considered in making its decision yesterday. That commitment applies to all EU countries, without exception, which means it can be invoked by non-NATO EU member-states that are widely assumed to be “neutral,” including Sweden and Finland.

For obvious reasons, Sweden and Finland have been unnerved by Russia’s actions in Ukraine, and discussions are underway in both countries about the possibility of joining NATO. However, unless Russia makes another dramatic military move – for example, in Georgia, in Belarus, or again in Ukraine – I rather doubt Sweden and Norway will opt for NATO membership. Nor is it entirely clear that Finland in particular, which shares a very long border with Russia, would be accepted into the alliance given the unanimity rule. It is therefore likely that one or both will remain within the EU’s security umbrella – such as it is – but not NATO’s.

I suspect that that France’s invocation of Article 42.7 is going to make the EU’s collective security provision, which was not something that many took very seriously before yesterday, more politically salient. That may have some bearing on Swedish and Finnish deliberations on NATO membership, the argument being that we already have a security guarantee from our EU partners (although I doubt many Swedes or Finns would find that terribly reassuring). It may also have some impact on EU deliberations over whether to accept new, militarily vulnerable members such as Ukraine and Georgia – it is going to be more difficult to represent EU accession as simply an economic or political matter without security implications. (The Paris bombings, coupled with the migrant/refugee crisis and the growing potency of nativist movements across Europe, is in any case going to make further EU expansion even more difficult than it already was.)

Most importantly, I suspect that the invocation of Article 42.7 is going to highlight institutional tensions between the EU and NATO in the security field, including but not only their distinct collective security provisions, as well as the extent to which the EU’s modest defense capabilities are out of balance with its considerable defense commitments.

Indeed, I suspect that few EU citizens were aware of Article 42.7 before yesterday. And I suspect that even fewer realize that each EU member state is legally obligated to come to the defense of Sweden and Finland. Likewise, how many Swedes and Finns are aware that their countries have a collective security commitment to Romania and Bulgaria.

At the least, yesterday’s announcement is going to mean that European leaders will be more aware that the EU is not simply a political and economic project but a security one as well.