LONDON (Reuters), a Russian ally warned NATO Thursday that if Sweden, Finland and the U.S.-led alliance were to join it then Russia would need to strengthen its regional defenses. Russia could do this by deploying nukes.

Finland and Sweden, who share a border of 1,300 km (810 miles) with Russia, are considering joining NATO. On Wednesday, Finland’s Prime Minister Sanna Marin announced that a decision will be made in the coming weeks.

Dmitry Medvedev (second chairman) of Russia’s Security Council stated that if Sweden or Finland joined NATO, Russia would need to increase its land, navy, and air force in the Baltic Sea. This will restore military balance.

Medvedev raised the issue of nuclear danger by stating that it was impossible to talk about a “nuclear-free” Baltic. Russia’s Kaliningrad exclave is sandwiched between Poland, Lithuania and Russia.

“There can be no more talk of any nuclear–free status for the Baltic – the balance must be restored,” said Medvedev, who was president from 2008-2012.

Medvedev declared that Russia “has not taken such steps” and would not do so in the future.

“If our hand has to be forced, well… note that this was not we who suggested it,” he said.

The Russian invasion of Ukraine on February 24th has left thousands dead, and displaced many millions of people. It also raised concerns about a larger confrontation between Russia (and the United States).

Putin claims that the Ukraine “special military operation” is needed because Russia was using Ukraine as a threat to Russia. Moscow also had to protect against Ukraine’s persecution of Russian-speaking citizens.

Ukraine claims it opposes an imperial-style land grab, and Putin’s accusations of genocide seem absurd.