Within the context of military doctrine, military strategy is the highest-level national concept of the use of military power. It includes setting the composition of the military and its deployment; high-level regional objectives in war; military research and maintaining an industrial base.
It operates at the level of geographic theaters of operations or specialized functions. The smallest units to have a strategic role are usually field army and larger units on land. Strategic strike involves smaller, specialized units that can independently strike deep in the enemy rear areas. The most obvious example are long-range bombers and guided missiles, but special operations forces can carry out strategic missions, and either exfiltrate, or stay behind and raise guerrilla forces.
Strategy is still considered associated with using military means to influence behavior of other actors, but the term "grand strategy" goes beyond military means as a way to implement politics (or policy).
In contrast, [military] strategy is the highest level of how to structure and deploy a nation's military forces. It must first deal with the strength, composition, and capabilities of those forces, and then decide on a command structure, which is often based on geographic areas of operations, and often domestic or military politics. For example, a basic Allied strategic decision in the Second World War was to divide operations into European, Pacific, and Mediterranean, but, in the Pacific, it was necessary to divide into Southwest Pacific and Pacific Ocean areas. The necessity came from the need to manage the notable ego and skills of Douglas MacArthur.
Strategic generations in the modern era
First generation warfare
The first minimally industrialized warfare involved rigidly linear troop movements (e.g., line and column), principally direct fire muskets and small cannons. tactics of line and column; which developed in the age of the smoothbore musket. Napoleon introduced some of its concepts, including the division as an early form of combined arms operations, synchronization with the first portable and accurate watches, and the beginnings of decentralization to the level of corps.
Second generation warfare
This was a gradual transition in movement, as artillery and repeating rifles greatly increased the power of the defense. Technology became important in support (e.g., railroads) and communications (e.g., telegraph).
It is difficult to put an exact start on this period, except it is fairly clear that first-generation methods became obviously ineffective at the Battle of Gettysburg. Admittedly, some forces were still learning about the even greater power of the defense in 1914.
Third generation warfare
Usually considered to have started with non-linear movement, by combined arms forces, and attacks in the enemy's rear by air or special operations forces, the most common start of this phase is associated with German blitzkrieg operations in 1939. Command was increasingly decentralized.
There were earlier hints of breakthrough operations, such as German use of chemical weapons at the Second Battle of Ypres in 1915, the U.S. Army (Union) army to use large explosives with penetration Battle of the Crater in 1864, or British use of massed tanks at the Battle of Cambrai in 1917. All these potential breakthrough operations failed due to failures of communications, understanding of weapons capability, and unimaginative commanders.
Fourth generation warfare
Continuing the nonlinear trend of third generation warfare, this is characterized by extreme decentralization enabled by advanced electronics, special operations forces and non-national actors including revolutionary warfare, and continuous operations. In very different ways, Mao's revolutionary warfare, airmobile operations in Vietnam, and the first network-centric warfare in the Gulf War are all different fourth generation models. Some suggest that the extensive networking among "sensors and shooters", with much improved situational awareness, coupled with the use of precision-guided munitions, may be a fifth generation.