Like most former Soviet satellites, Poland has grown very suspicious of Russian intentions since the Kremlin annexed Crimea last year. Poles living near the 180-mile border their country shares with Russia became especially wary after their government, among others, accused Moscow of deploying nuclear-capable Iskander missiles in Kaliningrad.
That area — which borders Poland — is the westernmost part of Russia. It used to be part of Germany, but was annexed by the Soviet Union after World War II and is home to a key Russian seaport on the Baltic Sea.
From a windy hill outside the sleepy Polish village of Parkoszewo, one can see just how porous the border is. A wooded area is all that divides one country from the other.
But sneaking across remote parts of the frontier is no longer easy, thanks to six unmanned posts that have been erected outside Polish hamlets, including Parkoszewo.
The red-and-white metal structures look like radio towers and rise as high as 164 feet, says Polish Border Guard spokeswoman Agnieszka Golias. The cameras on the towers, she says, allow border authorities to scan as far as 12 miles into Russian territory.
Golias says the main purpose of the $5 million enhanced surveillance network — fully operational as of this month — is to curb smuggling and illegal immigration. But many Poles say their government should use the towers to keep tabs on their neighbor in other ways, too.
Mistrust is prevalent even in the Polish border town of Braniewo, where the two sides have mixed freely for years, thanks to a local no-visa requirement.
Braniewo's main supermarket is packed with Russian shoppers who, despite the devalued ruble, come here to stock up on better-quality foods and supplies than they find at home. Poles, in turn, drive to Kaliningrad to buy gas and cigarettes, which are much cheaper there.
Braniewo resident Krystyna Motyka admits to feeling a bit uneasy about the arrangement. The 64-year-old Polish retiree, who used to run a bread delivery business to Kaliningrad, says relations with Poland's northern neighbor used to be a lot better.
Nowadays, she says, "We just don't trust the Russians and there's a feeling anything could happen."
Anti-Russian sentiment ran so high in the nearby seafront town of Sopot that several business posted signs stating Russians were not welcome some months back. That annoyed Polish bartender Bartek Firmowski, 28, who responded by putting up a sign welcoming Russians to the beachfront club where he works.
Both the pro- and anti-Russian signs have since been removed.
"There is Russian society, which is Slavic — same as Polish — and in some way, we should feel like brothers and sisters, I mean like one bigger nation," Firmowski says.
But given Russian actions in eastern Ukraine, he wants Poland to beef up its military presence near the border.
"When I'm thinking about our history, I would say, yes, definitely," he explains. "If there would be more troops in Poland, I would definitely feel safe here."
So would Polish parliament member Arkadiusz Czartoryski.
"There's the old Roman maxim, 'If you want peace, prepare for war,' " he says.
He and some 14,000 Poles have joined or formed local militias. "Many of these volunteer groups have histories that go back to before World War II, but since the Russian intervention in [eastern Ukraine], many more have mushroomed," Czartoryski says.
Waldemar Zubek, a translator of military history books and a staff sergeant for a militia in a Warsaw suburb, says both the Polish government and military have become more welcoming of volunteer units than in past years.
Zubek doubts Russia would dare to invade Poland. But, he emphasizes, by forming more militias, "We have a chance to make something that helps in the defense of our country, and that's the point."