In eastern Poland, the terror threat has been raised, a Russian agent has been arrested and there is a fear aid supplies moving through the region and into war-torn Ukraine could be targeted with "acts of sabotage".
More than 1.5 million refugees have crossed from Ukraine and into Poland, but going in the opposite direction are the supplies essential to Ukraine's defence and to the survival of the people left behind.
Logistics experts from all around the world have converged on the city of Rzeszów. Some are happy to talk about what they're moving across the border, others are not.
And while goods are moving out of Poland, the American military is moving in.
This region is dealing with an escalating humanitarian crisis as well the new reality of being one of the last stops in Europe before Russia's war.
Residents along the far east of the country are reminded of their position daily as American fighter jets take off from a nearby military airfield and undertake surveillance flights.
The 5,000 troops of the United States 82nd Airborne Division are now based near Rzeszów and thousands more soldiers are expected to arrive in the area in coming months.
Spies and sabotage
The people within the overlapping and often grassroots networks coordinating aid going into Ukraine might be too busy to fathom the threats they face, but Polish officials have moved to protect them.
Since the war began, the Polish government has lifted two categories of terror threats.
Nationally, the cyberterrorism threat has been lifted to its second-highest setting and the government has moved the terror alert level in Rzeszów's region to Brava, which tells local authorities to act to prevent an attack.
"Of course we are nervous," Rzeszów city mayor Konrad Fijolek told the ABC.
He said the situation was tense.
"There is a danger of acts of sabotage because this is the corridor where the humanitarian aid goes to Ukraine and the situation is becoming more and more dangerous," Mr Fijolek said.
Of course, Russian warfare comes in many forms. While Vladimir Putin unleashes brute force over the border in Ukraine, spycraft and suspected cyberterrorism reach beyond the geographical bounds of his war.
On Thursday, Polish authorities arrested and charged an agent from Russia's military intelligence service GRU in the town of Przemyśl, one hour away from Rzeszów and 20 minutes from the Ukrainian border.
Przemyśl is the first Polish town Ukrainian refugees will pass through when crossing through the main gate at Medyka.
Of the 1.5 million people who have fled Ukraine over the past two weeks, more than 1 million of them are now in Poland and Medyka is the busiest crossing.
The town is old-world Poland. Many of the buildings in Przemyśl were spared in World War II and now they are serving as places of respite for Ukrainians caught in Europe's current war.
In the first few days of the Russian invasion, refugees and volunteers descended on Przemyśl and among them was an accused GRU agent.
According to Poland's Internal Security Agency, this suspected spy intended to travel into Ukraine after obtaining information — "the use of which, by the Russian secret services, could have a direct negative impact on the internal and external security and defence of our country".
Inside Ukraine, news outlets publish information about detained Russian "saboteurs" and how to spot potential agents.
In a local independent newspaper in Lviv, one story reads: "Please report potential Russian provocateurs."
"We ask all residents of Lviv regional and realtors for information about men aged 20 to 50, who can rent apartments in the region both personally and through intermediaries.
"Characteristically, these people speak Russian and do not speak Ukrainian."
Radio silence for truck convoys
There are countless operations to move supplies into Ukraine, some of them the result of one person's initiative, others involving cargo planes and UN aid convoys.
No matter their size, the resounding message is that much more is needed and the supply lines need to stay open.
Grzegorz Gruca from Polish Humanitarian Action has a great deal of experience bringing life-saving aid through war zones.
He is comfortable with the notion that sometimes to save lives, you have to risk them.
"We are a humanitarian organisation working in crisis places, such as Turkey, Syria, or South Sudan … we are part of a UN response system," Mr Gruca said.
"It's always a big risk, but we are saving human life. That's our role."
He said the obvious risk to drivers was on the Ukrainian side of the border, but his convoys were prepared for less conspicuous challenges in Poland too.
"This is something we always [take] into consideration," Mr Gruca said.
Mr Gruca said his convoys were seeing police presence every 20 kilometres and were often brought to the front of queues at the border to keep them moving.
The people and supplies moving into Ukraine are keeping the effort to defend the country going.
Rzeszów police Deputy Inspector Marta Tabasz-Rygiel told the ABC her teams were escorting convoys to the border.
"We are assisting the humanitarian convoys every single day," she said.
"We are aware of the danger. We have to be aware and act rapidly in the event of terrorism danger."
She said their focus was critical infrastructure relevant to the aid runs and locations where crowds of people are gathering, something happening all over Polish border towns as refugees stream into the country.
There have been suspected disinformation campaigns on Polish social media, believed to be attempting to incite hate towards the arriving refugees.
Cyberthreats 'attempt to gain intelligence' on logistics
Last week, cybersecurity research group Proofpoint said an unidentified state actor was targeting European officials with malicious software in an apparent attempt to disrupt efforts to assist Ukrainian refugees.
The group didn't identify the nation-state behind the attack but said it was similar to campaigns carried out by a hacking group that has previously worked in the interests of Russian ally Belarus.
Proofpoint researchers also said the attack on European officials may be an attempt to "gain intelligence regarding the logistics surrounding the movement of funds, supplies and people within NATO member countries".
"While the utilised techniques in this campaign are not ground-breaking individually [but] if deployed collectively and during a high-tempo conflict, they possess the capability to be quite effective," the researchers said.
Ms Tabasz-Rygiel said police in the Rzeszów region were now facing "a massive challenge".
"We've never faced a challenge like this before, but I'm also a wife and mother and I have my own fears," she said.
"Every day I hear the planes above my head. I know the border is only kilometres away."
ABC/Reuters
