Masked and armed men attempted to cross into Latvia from Belarus alongside 20 undocumented migrants on Monday.

“The (masked) escorts of the illegal migrants, who were located on the Belarusian side, were armed, issued threats to … soldiers, and also actively urged and drove the migrant group toward Latvia,” Janis Dombrava, Latvia’s interior minister, said on Tuesday. The group was stopped by the military.

Later, masked men managed to enter Latvia, destroying an electrical box and stealing surveillance cameras before returning to Belarus – an act of sabotage orchestrated by the country, according to Latvian officials. It was not clear if the second incident involved the same masked men as the first.

“Unlike many previous incidents, this time the provocation was particularly demonstrative and aggressive,” said Dombrava.

Since 2021, Belarus, Russia’s ally, has used migration as a tool to destabilise NATO’s eastern flank. It shares borders with Russia, Ukraine, Poland, Lithuania and Latvia – the latter considered Europe’s weakest link.

“The crisis at the EU [European Union] border with Belarus has been ongoing for five years. The situation in Latvia has been deteriorating since May of this year,” Bartosz Chmielewski, Baltics expert from the Poland-based Centre for Eastern Studies told Al Jazeera. “There has been a steady rise in border violations and the number of people crossing.”In September and October, “the number of border violations has already reached 12,000, a level equal to the total for the entire previous year”, he said.

According to Olevs Nikers, the Latvian president of the Baltic Security Foundation, “A Ceuta-style surge is physically possible, and we should plan for it.”He was referring to the recent crossing of tens of thousands of people from Morocco to Spain.

“But sustained low-level pressure may be the more effective strategy. It creates exhaustion, budget pressure and friction between allies. Poland’s renewed controls on its border with Lithuania are already an example of this.”He noted that Lithuania’s border with Belarus is four times longer than Latvia’s 173km (107 miles), yet pressure has been concentrated in Latvia.

“This looks less like spontaneous migration than a deliberate instrument, adjusted to test the neighbour perceived as most vulnerable,” Nikers said.

Any migration pressure from Belarus may cause bureaucratic chaos. Latvia, with a population of 1.8 million, would struggle with the reception, processing and providing medical aid to potential asylum seekers, he said.

The Latvia border with Belarus near Piedruja, Latvia [File: Ints Kalnins/Reuters] According to the Polish Border Guard, in 2021, almost 40,000 people tried to cross the border from Belarus. Thousands more crossings of undocumented people were never recorded.

Before Russia’s war in Ukraine began in 2022, Belarus built a system – including travel agencies, plane connections and visa programmes – encouraging migrants seeking a better life to cross into the European Union from the east. The scheme targeted people from the Global South, or Latin America, Africa and much of Asia.

According to experts, the system has since been dismantled, but Belarus is still pressing migration when it can.

“A sudden influx of several thousand people into Latgale in winter would become a humanitarian and political problem before it became a border-security problem,” Nikers added.

Out of all of NATO’s eastern flank countries, Latvia seems the least prepared for provocations coming from the east.

“Until now, Latvia remained on the sidelines, as the pressure was primarily focused on Poland and Lithuania. Now it finds itself in the spotlight, partly because it is unprepared, its border infrastructure is inadequate, and the resources of the border guard – even with military support – are dwindling,” Chmielewski said.

“Latvia struggles to execute major infrastructure projects … It shares the shortest border with Belarus, but has been unable to complete the necessary infrastructure there; this is due both to the challenging terrain and the state’s limited operational capacity.”Other experts said the migration pressure from Belarus might be a response to recent political developments in Latvia.

“The elections in Latvia were won by a coalition led by [Prime Minister] Andris Kulbergs, which seeks to maintain sanctions against Belarus. So Belarus uses both carrots and sticks to show it can destabilise the situation in the Baltics,” said Marta Jaroszewicz, assistant professor at the University of Warsaw’s Centre of Migration Research.

“For the past year, there have been periodic releases of Belarusian political prisoners, a process supported by the US administration. Belarus’s goal is the lifting of sanctions and the ability to transport its raw materials via Baltic ports, including through Poland. The objective is, in fact, the normalisation of trade.”Russian and Belarusian pressure on the EU has also changed over the years as migration pressure is only one of the tactics employed. Others include disinformation, arson, the recruitment of local citizens and GPS jamming, according to Nikers.

He said that “2026 is increasingly about airspace and infrastructure. The most important change is that Russia has moved from targeting what we believe to targeting what we depend on: cables, grids, navigation and airspace. It is also increasingly operating below the Article 5 threshold.”Established in the aftermath of World War II, NATO’s collective defence commitment, Article 5, was designed to ensure mutual protection among member states in response to the perceived threat of Soviet expansion, particularly in Eastern Europe during the early stages of the Cold War.

“This is an attempt at intimidation by Russia. And what deters Russia from aggressive actions on the eastern flank is the solidarity of European nations,” Chmielewski said. “That is what Russia fears most: that should it stage a more brazen provocation, solidarity will stretch from Lisbon to Stockholm, and the European Union will act as a united front.”