According to Defense Express, Russia has long relied on 4G modems with SIM cards to transmit intelligence from its drones. Evidence suggests preparations for strikes on Poland began months before the September 10 drone attack, which Warsaw described as an “unprecedented violation of airspace” and a “large-scale provocation.”Back in early July, reports surfaced in Poland that SIM cards from local mobile operators had been discovered in Russian drones shot down over Ukraine. Polish journalist Marek Budzisz cited a detailed July 2 report, which described where the drones were downed and confirmed that their wreckage contained 4G modems with Polish SIMs. In one case, a Lithuanian SIM card was also found.The report — whose authorship remains unclear but appears to come from a high-level source — concluded that the findings pointed directly to Russian preparations for drone flights over Poland and Lithuania, including tests of local mobile networks. It stressed the need to alert partners in both countries, which seemingly happened, given the document reached Budzisz a week later.Still, the revelations caused little stir in Poland. This was despite the fact that, as early as the summer, Russian drones had begun regularly crossing into Polish airspace. Some even detonated on the ground, including the August 20 incident near the village of Osiny in Lublin Voivodeship, just 40 kilometers from an airbase hosting a NATO air patrol.Russian Shaheds in Polish airspace. BackgroundPolish Armed Forces’ Operational Command put air defense systems and aviation on highest alert due to Russia’s night attack on Ukraine: Russian drones violated the country’s airspace. Search continues for downed drone sites.As a result of a Russian attack on the night of September 10, drone debris fell on a residential building in a village in Poland’s Lublin Voivodeship. No one was injured.Ukraine's President Zelenskyy says Ukraine is ready to help Poland develop an alert and air defense system. Meanwhile, European Commission President von der Leyen announces the EU will build a “drone wall” on the Russia border.Ukrainian President Volodymyr Zelenskyy commented on the violation of Poland’s airspace by Russian drones, stating that Kyiv had warned Warsaw about the UAV movements.