The Stand-in Attack Weapon (SiAW) is a tactical air-to-surface missile under development for the United States Air Force (USAF) by Northrop Grumman.

[1] In May 2022, the USAF awarded contracts to L3Harris Technologies, Lockheed Martin and Northrop Grumman to begin the first phase of development for the Stand-in Attack Weapon (SiAW).

[3] On 28 September 2023, the USAF awarded a US$705m contract to Northrop Grumman to develop and test the SiAW.

It will have a shorter range than standoff weapons, being fired by an aircraft after penetrating enemy airspace.

The design leverages work on the United States Navy's AGM-88G Advanced Anti-Radiation Guided Missile - Extended Range (AARGM-ER).