Ukrainian border guard Oksana Ivanets winds her way past a 2-meter-tall green metal fence topped with coiled razor wire and through serpentine, timber-lined trenches to a bedroom-sized bunker built to withstand a direct hit from a 152-millimeter artillery shell.
Out of a small window that looks north into a sprawling field of golden sunflowers, she points to a spot on the horizon where Ukraine ends and the territory of its adversary begins.
