As a naval aviator, Smith flew carrier-based A-4 Skyhawk and A-7 Corsair II light attack jet aircraft during multiple deployments to the Mediterranean, North Atlantic, Western Pacific and Indian Oceans.

In December 1995, he assumed, concurrently, command of the NATO-led Implementation Force (IFOR) in Bosnia, a position he held until August 1996.

Smith's IFOR command in Bosnia was criticized by Richard Holbrooke for his refusal to use his authority to also perform nonmilitary implementation tasks, including arresting indicted war criminals: Based on Shalikashvili's statement at White House meetings, Christopher and I had assumed that the IFOR commander would use his authority to do substantially more than he was obligated to do.

Smith and his British deputy, General Michael Walker, made clear that they intended to take a minimalist approach to all aspects of implementation other than force protection.

Smith signaled this in his first extensive public statement to the Bosnian people, during a live call-in program on Pale Television — an odd choice for his first local media appearance.

[4] Prior to his retirement, Smith had previously served alongside General Clark for several years during the war in Bosnia and Herzegovina.

Smith has been one of the senior signatories of the March 31, 2009 letter urging the president to maintain the policy excluding homosexuals from the armed forces.