Montenegro is poised to become Nato's 29th member at a summit starting on Wednesday, despite domestic divisions and deep Russian hostility to the move.
The former Yugoslav republic of 650,000 people only has about 2,000 troops, but its accession will give Nato full control of the Adriatic coastline and of the entire northern coast of the Mediterranean, from Portugal to Turkey's border with Syria.
Officials inside Nato and its member states say the inclusion of Montenegro will also send a strong signal to Russia that the alliance is only getting stronger, and that the Kremlin should halt its alleged efforts to destabilise the Balkans.
Montenegro is now preparing for a trial – which could start this week – of people accused of planning a coup against the country’s pro-western government last year, in which prosecutors claim Russian agents played a leading role.
Storm parliament
The plotters allegedly planned to storm parliament on the evening of hard-fought elections last October and kill then prime minister
Milo Djukanovic
, before seizing power and halting Montenegro’s journey towards Nato.
Two indicted Montenegrin opposition leaders deny involvement in the plot, calling it a hoax that allowed Mr Djukanovic’s allies to retain power while portraying themselves as victims of a Russian-led conspiracy. They also want a referendum on Nato accession, which polls suggest splits Montenegro down the middle.
The Kremlin also dismissed the alleged plot, while lashing out at a country that has attracted many Russian investors and holidaymakers to its spectacular coastline since it split from Serbia in 2006.
Without giving any evidence for her claims, Russian foreign ministry spokeswoman Maria Zakharova declared last month that "a clearly unfavourable situation for Russian citizens is developing in Montenegro" where diplomats had noted "a surge of anti-Russian hysteria".
Calling Montenegro's decision to let Russian visitors stay longer without a visa "a trick", Ms Zakharova said: "We cannot exclude possible provocations, detention on dubious grounds and the possible extradition of Russian citizens to third countries, particularly the United States. "
‘Strategic consequences’
Russia’s foreign ministry also accused Montenegro’s leaders of destroying the two nations’ friendship by joining Nato, and warned: “Moscow cannot ignore the strategic consequences of this step. Therefore, we reserve the right to take decisions aimed at protecting our interests and national security.”
US president Donald Trump is due to attend the Brussels summit on Thursday. He has softened campaign rhetoric that saw him dismiss Nato as "obsolete" and his officials have strongly backed Montenegro's membership,
In a letter to US senators in March, secretary of state Rex Tillerson wrote: "Montenegro's participation in the May Nato summit as a full member, not an observer, will send a strong signal of transatlantic unity and that no third parties have veto power over Nato decisions."
