German squad defensive tactics stressed the importance of integration with larger plans and the principle of posts scattered in depth. The individual Schützengruppe (squad) was expected to dig in on a frontage 30 or 40 meters, this being the maximum that a squad leader could effectively oversee in a defending battle. Major landmarks, such as single trees or crests were best shunned as too attractive to enemy fire. During the digging, one member of the squad was to stand sentry, preventing surprise from ground or air. Gaps between squads might be left, although covered by fire. Key to the defense was the location of the machine gun, which would be given several alternative positions, perhaps 50 or more meters apart, that were identified from the outset. It would cover longer range targets, while the riflemen, who might well be held further back, were concerned mainly with sweeping the terrain at close and very close range.

In the latter part of World War II, there was particular emphasis on resistance to armor. Ideal defensive positions were therefore on a tank-proof obstacle, equipped with at least one anti-tank weapon, capable of all round defense, and having artillery support directed by a forward observer. Active patrols with anti-tank weapons, as small as a single squad, were to be encouraged to intercept enemy tanks probing a defense.

The basic aggressive infantry squad tactics of all nations were devised with similar ends in mind: they were solutions to the problems of how to advance by means of fire and movement, and dislodge the enemy from his position. In World War II, the German squad would play its part by winning its Feuerkampf or firefight and occupying key positions during battles, never hesitating when they launched themselves on the offensive. When moving on the battlefield, the German squad had two main formations; advancing in the "Reihe", or loose single file formation, and "Schützenkette", or skirmish line. In the "Reihe" the squad leader took the lead, followed by the machine gunner and his assistants; these were followed by the riflemen, with the assistant squad leader bringing up the rear. The Reihe was highly practical for moving along tracks, presented a small target from the front, and allowed the squad leader to take decisions, directing the squad as needed. In all instances, the men were to take advantages of terrain, keeping behind contours and cover, rushing across exposed areas when alternatives were lacking.

From the single file formation (Reihe), the squad could easily be deployed into the "Schützenkette", or skirmish line. With the machine gun deploying on the spot, the riflemen could come up to the right, left, or both sides, bringing their weapons to bear. The result was a ragged line, with the men about five paces apart, taking whatever cover was available. The advance to contact was in bounds, from one visible objective to another, with a new objective specified as soon as the leaders had reached the first. Where resistance was serious the advance became fully fledged "fire and movement", either with a whole squad taking part, or a machine gun team down and firing while others advanced. Although grenades were best thrown from behind cover, they could also be used on the move. The soldier was instructed to grasp his rifle in the left hand and the grenade in the right, using the fingers of the hand holding the rifle to pull the fuse cord at the opportune moment. In circumstances where showers of grenades where needed, the order "Handgranaten!" from the squad leader would prompt the men to throw.

German strategy in World War II combined two concepts: the traditional "Decisive Maneuver", developed by Prussian General von Moltke in the 1850s, and the "Armored Concept", usually known as Blitzkrieg, proposed by Heinz Guderian in the late 1920s. Both required rapidly mobilized forces to attack on consecutive fronts, mounting a concentrated surprise attack on one front, defeating the enemy in a few days or weeks, before regrouping to attack on the second front, thus avoiding a costly defensive two-front war which Germany would inevitably lose.

Both strategies demanded that Germany be the aggressor, a position in line with the Third Reich’s xenophobic and expansionist ideology. Germany had the vital advantages of surprise and of choosing the time, place and conditions of the battles. Its opponents pinned their hopes on neutrality, diplomatic skills and static frontier defenses. They were psychologically unwilling to fight, and reluctant to prepare for war.

In the 1790s, the French army pioneered the use of the division, a self-contained unit of several regiments combining infantry, cavalry, and artillery. As part of his new military tactics, Napoleon developed this concept further, establishing a system of army corps, each made up of several divisions. The corps system meant that parts of the French army, which “lived off the land” instead of relying on fixed supplies, could take separate routes to their objective, reducing the risk of exhausting the ability of the areas they marched through to support them. This flexibility and the speed of the French armies left Napoleon’s enemies often seeming sluggish.

Napoleon also expanded the French artillery, and by 1805 the army had 4,500 heavy guns and 7,300 medium and light. A string of victories, most notably Marengo (1800) and Austerlitz (1805), left the successive coalitions formed against him reeling. Napoleon also realized the destruction of the enemy’s field armies should be his main objective, rather than allowing himself to be delayed by protracted sieges. Yet the strain on France’s resources began to show. An estimated 20 percent of Frenchmen born between 1790 and 1795 died in the wars. Increasingly, Napoleon’s soldiers were foreign, less well-trained and less motivated than the French. After 1808, divisions were standardized to two brigades, and the numbers of companies per battalion reduced to make command easier. The result was a less flexible force, and Napoleon’s later battles tended to be elephantine affairs, with large masses of men hurled headlong against the enemy, and far fewer flashes of sheer brilliance. At Borodino, in the Russian campaign of 1812, some 250,000 men fought on a narrow front just 5 miles (8 km) wide, leading to heavy losses on both sides.

The English tactics against Napoleon entailed the massive use of light infantry, specially from the late 1790s, and in 1800 an experimental corps was set up armed with new rifled muskets, more accurate than the prevailing smooth-bores. The defensive tactics of the English, led by the Duke of Wellington, were almost unmatched. They realized the use of a reverse slope defense, and made use of one whenever they could, to conceal their numbers and protect their men from French artillery. However, the British rarely missed an opportunity to counter-attack, and many French columns found themselves cut up by musket volleys, then attacked with bayonets.

The British favored line over column tactics and also paid more attention to logistics, not relying so consistenly on foraging, which, in the guerrilla-infested hills of Spain, had badly failed the French forces. In 1813 the Prussians created regiments of Jäger, volunteer riflemen, as a riposte to the French tirailleurs (shooters). Attrition, the exhaustion of French resources, British naval superiority—most notably demonstrated at Trafalgar (1805)—and Napoleon’s strategic greed led to his downfall in 1814, and his return from exile for the “Hundred Days” ended similarly in defeat at Waterloo in 1815.