Multi-region Azure Government and DoD cloud architecture enforcing USACE Impact Level 4 and 5 security boundaries with strict trust zone separation. ExpressRoute circuits connect on-premises CorpsNet and Active Directory through DISA BCAP to segregated IL4 zones in Azure Gov Virginia and Texas, and IL5 zones in DoD East and Central regions. Hub-spoke VNet topology with centralized security stack including Azure Firewall, Sentinel, Defender for Cloud, and Conditional Access enforces zero-trust boundaries between CUI and classified workloads. Fork this USACE-compliant reference architecture on Diagrams.so to customize subnets, gateways, and PaaS services for your DoD authorization boundary. Demonstrates FedRAMP High and DoD SRG compliance patterns with separate App Gateways, Key Vaults, and SQL databases per impact level.