Sweden's 200-year-old posture of military neutrality has been eroding amid European integration, and a perceived new threat from Russia has politicians now talking about abandoning it altogether and joining NATO.
Swedish forces have been taking part in peacekeeping, military exercises and some NATO-led missions since the 1990s as the country has joined regional and international forces to reduce its vulnerability in a still-volatile region more than two decades after the Cold War ended.
But fear of a resurgent Russia is rife in the former Soviet republics across the Baltic Sea, and Moscow's air and naval forces have stepped up patrols near and into Baltic states' airspace and maritime zones over the last two years as relations between Russia and the West have become newly hostile.
Since the Kremlin seized and annexed Ukraine's Crimean peninsula in March 2014, public opinion has shifted from broad opposition to Swedish membership in the North Atlantic Treaty Organization to one in three Swedes now telling pollsters they favor joining.
"I think it's the combination of the perceived threat from Russia and a discussion about the armed forces' inability to carry out their tasks which leads to more Swedes being in favor of Swedish NATO membership," Ulf Bjereld, a political science professor at Gothenburg University, told Swedish Radio after the latest SOM Institute survey on Western military alignment.
After Swedish media gave broad coverage to rising pro-NATO sentiments, Russia's ambassador to Sweden, Viktor Tatarintsev, warned that Moscow might react militarily if Stockholm were to abandon neutrality and join the alliance.
"I don't think it will become relevant in the near future, even though there has been a certain swing in public opinion. But if it happens there will be counter measures," Tatarintsev told the Dagens Nyheter newspaper in June. "Putin pointed out that there will be consequences, that Russia will have to resort to a response of the military kind and reorientate our troops and missiles. The country that joins NATO needs to be aware of the risks it is exposing itself to."
This week, the leader of a key opposition political force, the Center Party, said she would advocate a move toward NATO membership when the party faithful gather for their annual policy conference.
"We lack the ability to defend ourselves for a longer period of time. At the same time, NATO is very clear about the fact that Sweden cannot expect military support if we are not full members of the organization. We can no longer close our eyes to that," party leader Annie Loof wrote in an op-ed published Tuesday by Svenska Dagbladet.
The Moderates -- the largest of the four parties in the opposition coalition -- already support joining NATO, as do the Liberals. The last of the quartet, the Christian Democrats, also plans to revisit the issue at its party conference in October, leader Ebba Busch Thor told the TT news agency.
The ruling coalition of Social Democrats and Greens remains opposed to NATO membership. But they have been supportive of closer engagement with the Western defense alliance and joined four other Nordic countries in April in announcing military collaboration in "direct response to aggressive Russian behavior," Swedish Defense Minister Peter Hultqvist wrote in an opinion piece carried then by the Aftenposten newspaper.
The pact unites Sweden, Denmark, Norway, Iceland and Finland in a common mission to bolster defenses against potential threats from Russia.
NATO-member Baltic states reported a fourfold increase in provocative warplane flights and maritime intrusions last year. Two Russian SU-24 fighter bombers penetrated Swedish airspace in September 2014 in a maneuver that former Foreign Minister Carl Bildt called "the most serious aerial incursion by the Russians" in a decade, The Local news website reported at the time.
In October, the Swedish navy and maritime security forces fanned out across the vast Stockholm archipelago in search of what was suspected to be a Russian submarine that had been spotted near the Swedish capital. The weeklong hunt found no trace of the vessel but authorities expressed certainty it was a clandestine Russian mission.
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