Wilno in September 1939 was a Polish city of churches, synagogues, and Baroque facades, the capital of a voivodeship Poland had recovered only twenty years earlier. The Polish defenders concentrated their strength in the west, where Hitler's armies had been pouring across the border since September 1. Then on September 17, in accordance with the secret protocol of the Molotov-Ribbentrop Pact, the Red Army crossed Poland's eastern frontier. Wilno suddenly faced an invasion the country had not planned to fight. The garrison numbered 14,000 soldiers and militia volunteers, but only 6,500 had weapons. Okulicz-Kozaryn ordered the unarmed volunteers to stay out of the fighting. He could not arm them, and he would not see them killed for nothing.

On September 18 around five in the afternoon, reports reached the Polish command that Soviet armored scouts were approaching from the east. The forces sent against Wilno were enormous: two cavalry divisions, three armored brigades, supporting infantry, all under commanders with revolutionary-era titles like Komandarm and Kombrig. Okulicz-Kozaryn faced an impossible calculation. Should he hold the city against odds that guaranteed defeat, or withdraw and preserve his men for another fight on Polish soil? He chose withdrawal. The Border Protection Corps, the most experienced soldiers in the garrison, would screen the retreat toward the Lithuanian frontier. The general dispatched Podwysocki to inform the Soviets that Wilno would not be defended. The bullet that nearly killed Podwysocki changed everything.

Podwysocki returned to a city his commander had effectively abandoned. Most of the troops were already moving toward Lithuania. He could have followed them. Instead he gathered what forces he could find and prepared to fight. The first Soviet attack came that evening and was repulsed. The defenders held the bridges, the most defensible chokepoints in a river city, while Soviet armor probed for openings. By nightfall the Soviets had the airfield and the Rasos Cemetery, the resting place of generations of Wilno's poets and patriots. By the morning of September 19, fresh Soviet infantry and cavalry had arrived to reinforce the armor. The poorly coordinated Polish defense, scratched together from whoever had stayed, collapsed by the afternoon. Some defenders surrendered. Others slipped away toward Lithuania. The city belonged to the Red Army.

Polish historians have argued about Wilno ever since. With proper organization, the city's natural defenses might have held the Soviets for several days, the way Grodno did just to the south. But days, not victory, were the most that could have been bought. The Soviets soon transferred Wilno to Lithuania under their Mutual Assistance Treaty, and Lithuanian troops marched in on October 27 and 28 to banners that read 'Inhabitants of Vilnius welcome the Lithuanian Army.' Within a year, Lithuania itself would be Soviet. The men who fought Podwysocki's brief defense were not heroes of victory; they were witnesses that someone had refused to leave the city undefended. In a war Poland could not win, the gesture mattered.