First Sacred War vs Paekche–Tang War

The alliance demonstrated doctrinal flexibility by shifting from direct siege tactics to chemical warfare. Kirrha failed to adapt to the changing conditions.

Tang's flexible doctrine combining amphibious and land warfare rendered Paekche's static wall defenses obsolete. Silla maintained the initiative with rapid transit and encirclement tactics in rugged terrain. Paekche initially shifted to guerrilla resistance but lost flexibility after maritime isolation; Yamato's outdated naval doctrine prevented adaptation.

Siege/Challenge

Battle of Annihilation

The Alliance's Schwerpunkt was Kirrha's water source. Instead of the center of resistance (walls), an indirect approach targeting vital infrastructure was adopted.

The Tang-Silla alliance correctly identified and struck Paekche's center of gravity — the political and military capital Sabi — through a joint offensive. Coordinated naval and land operations rapidly collapsed the enemy's core. Paekche failed to mass its defense forces and only offered a tactical delay with Gyebaek's last stand.

Finding and poisoning the water pipe constitutes a classic deception and ruse. According to some sources, cutting and then restoring the pipe with poison was a sophisticated maneuver to mislead the enemy.

The Tang fleet's deceptive routing and choice of landing site achieved strategic surprise. Silla's unexpected attack through a mountain pass further divided Paekche's defense. Yamato's naval expedition suffered from intelligence gaps and tactical deception, leading to its entrapment at Baekgang.

The sudden and mass diarrhea caused by hellebore delivered a shock effect that collapsed the defense order. A biochemical rather than a conventional shock element was employed.

The Tang fleet's sudden attack at the Geum River mouth shattered Paekche's defensive lines, and the amphibious assault paralyzed the enemy's central command. At Hwangsanbeol, Silla cavalry's swift shock charge overwhelmed outnumbered Paekche infantry. At Baekgang, coordinated arrow and incendiary attacks from Tang warships dispersed the Yamato fleet on the first day, seizing psychological dominance.

Diverting the Pleistos River or exploiting water sources gave the alliance a 'ground' advantage. The mountainous terrain added to siege difficulties, but control of water proved decisive.

Favorable wind and current conditions during the 660 campaign allowed the Tang fleet a swift and safe crossing of the Yellow Sea. Although Paekche's capital Sabi lay inland on the Geum River, defenses at the river mouth could not stop Tang's naval power. At Baekgang, the narrow river mouth constrained Yamato's fleet maneuverability, enhancing Tang's tactical advantage. The mountainous terrain slowed Silla's eastern advance but reduced Paekche's defense depth.

The detection of the water pipe epitomizes 'know your enemy'. The alliance learned Kirrha's vital infrastructure while Kirrha remained uninformed of alliance plans.

Tang and Silla shared comprehensive intelligence on each other's military status and enemy vulnerabilities. Silla's informant network in the Paekche court and Tang reconnaissance reports revealed critical weak points. Paekche was unaware of Tang's mobilization, and Yamato's long-range intelligence efforts were inadequate.

The alliance quickly established a naval blockade, but the land siege remained static. Interior lines advantage belonged to Kirrha yet was unused; the alliance on exterior lines executed a slow but methodical maneuver.

Tang forces disrupted Paekche's defensive order with a rapid amphibious landing and advanced quickly toward the interior. Silla's army, crossing mountain passes, executed a simultaneous offensive that trapped the enemy. Paekche lost all maneuver space around the capital. During the resistance, late-arriving Yamato reinforcements failed to provide the necessary freedom of movement for interior defense.

Religious fervor (avenging Apollo) provided high morale for the alliance, while the physical debilitation from poisoning rendered the 'friction' of war unbearable for Kirrha.

The quick capture of the capital by the Tang army shocked Paekche troops, leading to mass surrenders. General Gyebaek's death broke Paekche's organized resistance; King Uija's surrender extinguished the people's will to fight. Conversely, Tang's harsh occupation initially sparked popular resistance, but the decisive defeat at Baekgang and Prince Buyeo Pung's flight dashed the last hopes.

The alliance rendered the enemy physically incapable of fighting through chemical warfare, almost obviating conventional battle. Diplomatically, Solon's declaration of war and religious motivation bolstered alliance legitimacy.

The Tang Empire diplomatically isolated Paekche by allying with Silla and applied psychological pressure before the war. Emperor Gaozong's repeated warning edicts caused divisions within the Paekche court, weakening resistance will as some aristocrats surrendered. In contrast, Paekche failed to build a deterrent despite its alliances with Goguryeo and Yamato.