Painting by Numbers: A History of the U.S. Military’s Phasing Construct


Editor’s Note: This article is the third in a series from thinkers at the Center for a New American Security that explores the U.S. military’s phasing construct and the line between war and peace. Read the first and second articles here.


Ask any budding student of security or member of the military where the focus of conflict is, and you’ll hear an emphatic “phase III operations.” The period in which decisive combat operations are undertaken is the meat and potatoes of America’s military. Glorified historical battles typically occurred in this phase, and most training and equipment is designed to operate in high-end conventional combat. Yet these high hopes have not proven decisive over the past 15 years. As Paul Scharre explored in the first two installments of this series, the phasing construct does not reflect reality. It was once valuable as a tool for force planning, but it has been applied too broadly and without sufficient utility.

Phasing’s Origins: The Unipolar Moment (1992-1993)

The origin of the phasing construct rests in the early post-Cold War era. Following decades of conflict against the Soviet Union and in the immediate aftermath of Operation Desert Storm, the U.S. Department of Defense went back to the drawing board to assess possible crises and evaluate force structure in light of the unipolar moment. The 1992 National Military Strategy contained many of the underlying concepts that later took form in the phasing construct, namely the idea of rapid decisive victory. The 1993 Bottom Up Review (BUR) matured this vision and presented the first iteration of the phasing construct for major regional conflicts that continues to inform operational planning today.

The BUR identified a range of possible post-Cold War uses of military force, including peacetime presence operations, weapons of mass destruction deterrence, threats from major regional conflicts, and smaller crises that would require U.S. peacekeeping or stability operations. In the emerging world order, the United States was unsure which adversaries would threaten U.S. interests, so the BUR designed a force structure that could accommodate two nearly simultaneous regional contingencies, as well as steady state peacekeeping and presence operations.

To determine the appropriate force structure for this period, the BUR identified four “phases” of a major regional contingency and their respective tasks required. The model scenario was based on a major regional actor, such as North Korea or Iraq, invading a neighbor. The United States would flow resources into theater from forward bases and sea ports. Then, the United States would achieve a quick and decisive victory requiring little troop presence afterward. The campaign would be broken into four phases. Phase I entailed halting the adversary’s invasion. During phase II, U.S. combat and logistics resources would flow into the theater and diminish the enemy’s capabilities. In phase III, the United States would “decisively defeat the enemy.” The campaign would conclude with phase IV, in which some forces might remain to provide post-war stability.

While the campaign outlined in the BUR was intended to be generalizable, the phases were clearly influenced by the stunning U.S. success in the Gulf War only two years prior. An obvious shortcoming of this model is that a swift buildup of forces may not be replicated in a country with only a few forward U.S. bases nearby, not to mention prepositioned stocks, easy airlift or seaports, or ready supporting allies.

However, these were not its only limitations. The phasing construct was developed to estimate force requirements for conventional regional conflicts, not an overarching model for the conduct of war generally, great power conflict, or nuclear actors. The BUR did not provide an analogous model for peacekeeping or stability operations, the number of which were expected to increase under U.S. global engagement. Further, the BUR indicated an expectation to fund other actors, such as the United Nations, to carry out peace enforcement and transfer this task from U.S. forces. Finally, the requirement of fighting two wars required a quick, decisive victory in one theater before shifting the brunt of resources to the other fight, while maintaining steady-state strategic nuclear and presence operations. Rapid victory was expected, and conflicts were assumed to remain conventional competitions between state actors. The construct institutionalized many of these unrealistic assumptions that the phasing construct perpetuates today.

The details of the phasing construct have evolved over time as the concept has been refined incrementally to reflect a wider range of contingencies beyond the simple Gulf War model. As this happened, the phasing construct also took on a wider role, evolving from a model of a specific type of regional campaign to a broader model for military operations as a whole. The marriage of operational plans to day-to-day operations and extended stability operations has reinforced its usage beyond the regional conflicts for which it was designed.

Evolution of the Opening Stages of Conflict (1995-2006)

Phases I and II have changed slightly since their original conception in the 1993 BUR, as the timing of conflict onset has been delayed and the deterrence phase has been formalized. In the BUR, major regional conflict opened with hostilities in Phase I and required halting an invasion. In response, local forces would defend against the attack, and other U.S. forces would rapidly deploy into theater for the battle. In 1995, updates to Joint Publications (JP) referred to phase I as prehostilities wherein shows of force deterred conflict, which could include the deployment or sustainment of forces. In the 2001 JP 3-0, actions in this stage remained largely the same, but became deter/engage and finally simply deter in 2006, which it remains today. While the initiation of conflict has shifted to a later phase, phase I operations have maintained a focus on shows of force.

Phase II has evolved accordingly from focusing on stabilizing a front halted in phase I, as in the 1993 BUR, to being the phase in which hostilities begin today. In the original conception, the front was stabilized by building up forces and capabilities for the coming fight while also preventing the enemy from regaining the initiative and potentially degrading the enemy’s forces before a counteroffensive. This buildup phase was lodgment in 1995, but was changed to seize initiative in 2001, which it remains. Today, if offensive operations begin, they start in phase II, as U.S. forces seek to gain the initiative over an enemy. The principle, however, has been constant: enhance U.S. ability to operate while decreasing that of the enemy.

With these modifications to phases I and II, the construct in 2001 included four phases, shown pictorially as a spectrum of warfare. It looks relatively familiar to the contemporary viewer. Updated phases I (deter/engage) and II (seize initiative) were followed by the unchanged phase III (decisive operations) and phase IV (transition) operations.

Source: JP 3-0, 2001
Source: JP 3-0, 2006

Addition of Noncombat Phases (2005-2006)

The biggest changes to the phasing construct were its expansion from four phases of the 1993 BUR to the six-phase construct in use today, which went into effect with the 2006 updates to the JP 3-0 and JP 5-0. The new phases bookended the original four, and both new phases existed at the lower end of the conflict spectrum. Phase 0 shaping operations are steady-state operations that link combatant commander theater maintenance to operational plans. This idea is built on the premise that it is less costly to prevent war than to wage it. Actions in this phase typically include building partner capacity and humanitarian missions to engage local populations.

Phase 0 formalized attempts to prevent conflict during steady-state operations. Then-Deputy Commander of European Command General Wald described phase 0 operations in detail in late 2006, extolling their value in training allies and partners, building interoperability, and preventing extremism through population engagement. These concepts were similarly reflected in a number of other documents, including the 2006 Quadrennial Defense Review (QDR), which focused on helping shape the interests of countries facing “strategic crossroads.” While the 2006 QDR did not name phase 0 operations outright, it reflected thinking similar to the 2006 versions of JP 3-0 and JP 5-0, which do discuss phase 0 operations. The value of steady-state military operations in shaping the security environment to prevent conflict or enable decisive operations permeated official documents across the Department.

The 2006 Joint Publications update also added a phase V to extend post-war stabilization operations into two phases: phase IV stabilize and phase V enable civil authority. This clarified the important role of post-conflict stability operations. In the original BUR, phase IV operations were described as “provide for post-war stability.” Interestingly, the 1995 JP 3-0 had two phases following a “decisive combat and stabilization phase,” a follow-through phase and a posthostilities and redeployment phase. The 2001 JP 3-0 returned to one post-conflict phase known as transition, more similar to the original BUR model. Stability operations only comprised one phase from 2001 until the 2006 update.

The 1993 BUR assumed operations on the lower end of the conflict scale could be handled by multinational forces or would require few U.S. forces. This fallacy became starkly apparent as Operation Iraqi Freedom progressed. While the BUR said “some” troops may remain after major combat operations concluded, the decisive success of the initial invasion of Iraq was met with stunning challenges as an insurgency emerged out of the chaos of the regime’s collapse. The addition of Phase V was part of a broader focus on post-conflict stability operations that attempted to elevate their importance.

The 2005 Department of Defense Directive 3000.05 “Military Support for Stability, Security, Transition, and Reconstruction (SSTR) Operations” emphasized the need for all of the services to elevate stability operations to the level of combat operations. The 2006 updates to JP 3-0 and 5-0 emphasized the need for stability operations across all phases of conflict and the addition of phase V doubled the phases of conflict that specifically addressed it. Since the phasing construct was intended as an aid for force planning, this represented a concerted shift toward force considerations for operations beyond decisive combat.

As the thinking underpinning the construct changed, so did the depictions of the model. The 2001 document included an image depicting the phasing construct as the spectrum of warfare, but the 2006 update indicated the consecutive nature of the phases with arrows flowing from earlier phases to later ones. The parabola shape of force flows and military effort used today did not exist until the 2011 update to JP 3-0. Since the original role of the phasing construct was as a force planning tool, an image of overall force usage existed in the 1993 BUR. This image showed more forces required to win two nearly simultaneous major regional conflicts over time, who could then return to steady-state operations after victory. This usage mirrors the parabola image of force flows if only one conflict is considered.

1993 Bottom Up Review Force Planning
Source: JP 3-0, 2011.

Operational Paint by Numbers in an Age of Changing Conflict

The current iteration of the phasing construct has been in place since 2006, but its skeleton is built around the bones of the 1993 BUR. Phases help commanders determine resource allocation over time and conduct force planning. The changes that added noncombat-intensive phases indicate an understanding of the need to consider periods other than decisive operations. Operational art is just that — art. The phasing construct provides a “paint by numbers” model to help allocate resources during planning, but it cannot solve all conflicts. Current joint doctrine indicates phases will be carried out sequentially and marked by events that trigger transition from one phase to the next. The level of military effort shown in the parabola graphic is “notional,” but implies that phase III requires the most effort and time. Despite its continued evolution, the phasing construct still suffers from shortcomings. Its implication that phase III operations are the most demanding in effort and time is starkly at odds with U.S. experiences in Iraq and Afghanistan, and the phasing construct is of little utility for the gray zone tactics potential adversaries use to intentionally avoid U.S. phase III operations.

The phasing construct was intended for a conventional campaign against an outmatched state actor with stronger U.S. forces, assured access and logistics, and little need for messy state-building after the conflict or extended competition beforehand. Over time, a construct designed for a repeat of the Gulf War morphed into a larger model of war. Only immediately after the Cold War was this specific model possible. As the sole superpower fresh from delivering a roundhouse kick to the world’s fourth-largest military, the United States was capable of making these assumptions. But today, these assumptions are completely divorced from the reality of strategic competition or long guerrilla wars. Looking forward, the U.S. military should explore new paradigms for conflict and competition, which coming articles in this series will do.


Lauren Fish is a Research Associate for Defense Strategies & Assessments at the Center for a New American Security.

Image: DOD Photo by Sgt. Darron Salzer