Siege and Storm Warfare: A Basic Overview

Siege and storm warfare is a classical military strategy involving a two-phase approach to capture a fortified position, such as a city or dense urban area. The goal is to break a defender who has the advantage of being dug in. This strategy has seen modern application in conflicts like the Battle of Mariupol (2022) and the Israeli ground operation in Gaza.

The Two Phases

Phase 1: The Siege (Investment)

This is the attrition phase. The attacking force surrounds the objective, cutting it off from reinforcements, supplies, and communication. The purpose is to weaken the defender for the final assault.

Key actions during a siege include:

Encirclment: Establishing a cordon to trap the defending force and any civilians inside.

Attrition: Weakening the defender through starvation, demoralization, and constant pressure like shelling and airstrikes.

Preparation for Assault: While the defenders weaken, the attacker gathers intelligence and establishes supply lines for the final push.

Phase 2: The Storm (Assault)

This is the decisive action phase. After the defenders have been weakened, the attacker launches a direct military assault to conquer the position. This phase is highly destructive and dangerous.

Key actions during the storm include:

Breaching the Defenses: Using concentrated firepower—tanks, airstrikes, artillery—to create a breach in the outer defenses.

Methodical Clearance: Small units of infantry advance slowly to clear the area. A key tactic is "mouse-holing," where soldiers blow holes through interior walls to avoid exposed streets. This is supported by armor and engineers.

High Casualties: This phase is exceptionally bloody for both sides, as the defender uses the terrain to set up ambushes.

Key Characteristics and Challenges

Devastating Impact on Civilians: Siege warfare is brutal for any civilian population trapped inside, who suffer from starvation, disease, and indiscriminate violence. This is a primary reason why the practice is heavily regulated under modern International Humanitarian Law (IHL).

The Defender's Advantage: Urban terrain is a "force multiplier." A small, determined force can inflict heavy losses on a much larger attacking force by using buildings for cover.

The Attacker's Dilemma: The attacker must choose between a prolonged siege (causing a humanitarian crisis) or a costly direct assault (risking high military casualties). Most campaigns use a combination.

Modern Context and International Law

While still used because it is effective against non-state actors embedded in urban areas, siege and storm tactics clash with the principles of IHL.

Distinction: Attacks must distinguish between combatants and civilians.

Proportionality: The collateral damage to civilians must not be excessive in relation to the direct military advantage anticipated.

Precaution: All feasible steps must be taken to avoid and minimize harm to civilians.

A siege that cuts off essentials for survival is generally considered a violation of IHL. The "storm" phase in a populated area creates immense challenges for adhering to these laws, often leading to accusations of war crimes when civilian casualties are high.

In summary, siege and storm warfare is a time-tested but brutally effective strategy. Its modern application creates profound legal and ethical dilemmas due to the inevitable catastrophic impact on civilian life.