Life on the European continent has been mostly peaceful in the 21st century. Many former Soviet republics have flourished since the fall of communism in the 1990s; the Baltic states, in particular, have made incredible progress and are largely unrecognizable from their 20th century selves. Many citizens however can remember the awful realities of life as a Soviet vassal state.

The three countries joined NATO and the European Union in 2004. All three use the Euro and have successfully reintegrated into Europe. Yet they are now at risk and must be among the West’s top priorities — Russia has demonstrated its desire to make Ukraine a vassal state through full-scale military action and may not stop its bloody campaigns.

Just as Vladimir Putin issued blood-curdling threats to Ukraine before his unprovoked assault, so too he has menaced the Baltic states. They are not generally named by Russian spokespeople, but the message is quite clear. Russia formally demanded on December 17 and has since reiterated and expanded its wish list, that any former Soviet republic is made neutral, that NATO troops depart with their equipment, and that they effectively are abandoned to the mercy of their huge, heavily armed neighbor.

So will Putin do it, thereby triggering a direct military clash with the NATO battlegroups in Estonia, Latvia, and Lithuania? Remember the contributor nations include the US, the UK, France, Germany, and Canada; an attack would very obviously trigger NATO’s Article 5 and a general war with Russia.

Ukraine is considered an Enhanced Opportunities Partner by the alliance, a status short of full membership. Putin knew he could attack without triggering a wider war (even if the US administration wanted it, American public opinion would be unlikely to support such a decision.) In crude political terms, the invasion was a risk that Putin thought he could take.

Any such case against the Baltics would be far harder to make, although it’s true that together they also have Russian-speaking citizens (1 million compared to over 7 million in Ukraine.) While all four countries share a dark history of occupation and a border with Russia, the Baltics have made immeasurably greater progress in aligning themselves to Europe and the West.

That is not to say they are safe. Putin made his thoughts clear in his written December list of demands after asserting Ukraine should never be allowed to join NATO (or any other countries for that matter) and calling for NATO withdrawal of the multinational battlegroups from Poland and the Baltic states (and now Romania.)

The alliance’s response has been forthright and there are now more than 22,000 troops in former Soviet republics and satellite states. Yet at their current size, they could probably not resist a large-scale Russian military attack and continue to represent — given their small size and location —NATO’s most vulnerable members states.

Leaders on both sides of the Atlantic have repeatedly reassured the Baltic nations that they have nothing to fear and NATO will come to their aid should they need to invoke Article 5, but given the recent historic memory of Russian occupation and oppression, it is hardly surprising that the peoples of Estonia, Latvia, and Lithuania feel exposed.

Despite huge strides over the last few decades, the little Baltic states have good reason to be concerned. For now, Russia is busy with Ukraine. That may change and NATO should consider greatly expended measures to deter.