According to military sources, plans on the table in Madrid include an expansion and rebranding of the 40,000-strong NATO Response Force, possibly to 240,000. The name will likely change to the Allied Reaction Force (ARF).
The eight battlegroups -- increased to 25,300 personnel following the Kremlin’s annexation of Crimea in 2014 -- will likely be boosted with thousands more troops.
NATO Secretary-General Jens Stoltenberg has said that NATO allies will agree “to strengthen battlegroups in the east up to brigade level.” A brigade can be between 3,000 and 5,000 personnel.
The Madrid summit comes as tensions between Moscow and the West rise after the European Union halted the transport of steel and ferrous metals through Lithuanian territory to the Russian exclave of Kaliningrad as part of the fourth package of EU sanctions against Russia.
The Kremlin has threatened to retaliate against the sanctions. Some in the West fear that the Kremlin could be planning military action to secure a land corridor between its ally Belarus and the Kaliningrad region via the so-called Suwalki Gap, a 65-kilometer (40-mile) strip of land in Poland along the border with Lithuania.