APPROACH, in military language the phase during which troops are moving forward from their assembly positions or con centration areas towards the enemy, and lasting until they deploy for battle. An alternative term is "approach march." With the smaller units, of course, in these days of long-range weapons, their own "approach" takes place on the battle-field, and only begins after the force of which they form part has deployed. In a broad sense, the "approach" covers all movements and man oeuvres before, and when out of, contact with the enemy. It is thus the province of strategy, just as the attack and the defence are the province of tactics. Under this definition a retreat which lures the enemy on to a chosen battlefield or gains time for a decisive blow elsewhere, is an "approach." The term may also, justly, cover measures by which the enemy's morale is under mined.