Security Cooperation Definition: 2025 Global Spending Context
Security cooperation refers to state-to-state defense engagement, and in 2025 it plays out against a backdrop of $2,740.0bn in combined military expenditure across the 149 countries SIPRI tracks.
Key takeaways
- Security cooperation is state-to-state defense engagement — alliances, arms transfers, training, and joint exercises — set against $2,740.0bn in 2025 world military spending across 149 countries.
- The $2,740.0bn figure is our calculation from SIPRI country-level data, not a total SIPRI itself publishes.
- 2025 spending in this dataset is reported as actual, not an estimate, unlike 2026-2027 projections elsewhere in the series.
- The total is a floor: North Korea and other spenders with data gaps are excluded, so real global spending is higher.
- Security cooperation spans alliances, arms sales, training/advising, joint exercises, and capacity-building assistance.
Verdict
Security cooperation is the network of state-to-state defense engagement — alliances, arms transfers, training, and exercises — operating within a 2025 global military spending base of $2,740.0bn across 149 countries, our calculation from SIPRI data rather than a SIPRI-published total. Because North Korea and several other spenders are absent from the dataset, this figure understates true world spending.
At a glance
| 2025 world total | $2,740.0bnConstant 2024 USD |
|---|---|
| Countries included | 149SIPRI-reported series |
| Data status | ActualNot an estimate year |
| Attribution | Our calculationFrom SIPRI country-level data |
Security cooperation is the umbrella term for state-to-state defense engagement — alliances, arms transfers, training, joint exercises, and capacity-building programs conducted between governments rather than within a single country's own forces. In 2025, this activity plays out against a backdrop of $2,740.0bn in combined military expenditure across the 149 countries SIPRI tracks — our calculation from SIPRI country-level data, not a figure SIPRI itself publishes as a world total.
01 What Is Security Cooperation? A Working Definition
Security cooperation describes the range of activities through which states work with other states' militaries and security forces, short of direct combat involvement. It spans formal defense pacts and alliances, foreign military sales and arms transfers, training and advising missions, joint exercises, and capacity-building assistance meant to professionalize or modernize a partner's forces. The term is distinct from "security assistance," a narrower category usually referring specifically to funding, equipment, or training provided to another state, and from "collective defense," which implies a binding mutual-obligation treaty structure such as NATO's Article 5.
What unites these activities is that they are relational: security cooperation only exists between two or more states (or a state and an international body), not within a single defense establishment acting alone.
02 Why Scale Matters: The 2025 Global Military Spending Backdrop
Security cooperation doesn't happen in a vacuum — it operates within, and is shaped by, the total volume of resources states devote to defense. In 2025, SIPRI reports military expenditure data for 149 countries, and summing those figures yields $2,740.0bn in constant 2024 US dollars. That scale is the operating environment for every alliance commitment, arms sale, and joint training program: a bilateral training mission or a multilateral pact is a transaction (or a standing arrangement) layered on top of this much larger base of national military budgets.
The figure is not an estimate for a future year — 2025 spending in this dataset is reported as actual, not projected — which distinguishes it from 2026-2027 figures elsewhere in this dataset that must be flagged as estimates.
03 Forms Security Cooperation Takes: Alliances, Aid, and Joint Exercises
- Formal alliances — treaty-based mutual-defense arrangements, such as NATO, that commit member states to coordinated planning and, in some cases, collective response obligations.
- Arms transfers and foreign military sales — the sale, grant, or transfer of weapons systems, equipment, and technology from one state to another.
- Training and advising — deployments of personnel to train, mentor, or advise a partner nation's forces, often aimed at building institutional capacity rather than direct battlefield support.
- Joint exercises — coordinated military drills between two or more states' forces, used to build interoperability and signal alignment.
- Capacity-building assistance — funding or in-kind support intended to strengthen a partner state's own defense institutions, logistics, or governance over its security sector.
Each of these forms draws on national defense budgets that collectively make up the $2,740.0bn 2025 total, whether the spending shows up as a bilateral aid line item, a portion of a country's own procurement budget used for joint-exercise costs, or contributions to an alliance's shared infrastructure.
04 How the $2,740.0bn Total Is Calculated (and Its Limits)
The $2,740.0bn figure is our own sum of SIPRI's country-level military expenditure series for 2025, covering 149 countries, expressed in constant 2024 US dollars. It is not a total SIPRI itself publishes; it is a calculation we perform from SIPRI's underlying country data — each country's reported 2025 expenditure figure is added to the running total, and any country absent from SIPRI's series (rather than reporting zero) is simply left out of the sum, not counted as a zero.
This total is a floor, not a full accounting of world military spending. It is the sum of the 149 countries SIPRI reports for 2025; some spenders — including North Korea, which has no SIPRI series — are absent entirely, and several other states have data gaps. The true global figure is therefore higher than $2,740.0bn.
05 Security Cooperation in Context: Exploring the 2025 Rankings
Because security cooperation is fundamentally about relationships between states, understanding which countries account for the largest shares of the $2,740.0bn 2025 total helps contextualize where cooperation frameworks — alliance commitments, arms transfer relationships, joint training programs — are likely to carry the most weight in absolute budget terms. The 2025 world rankings break down each of the 149 countries' individual contributions to that total. For definitions of related terms used alongside security cooperation, see the broader glossary.
Frequently Asked Questions
- What is the definition of security cooperation?
- Security cooperation is state-to-state defense engagement short of direct combat involvement — including formal alliances, arms transfers, training and advising, joint exercises, and capacity-building assistance.
- How much was global military spending in 2025?
- Summing SIPRI's country-level data for the 149 countries it reports on for 2025 gives $2,740.0bn in constant 2024 US dollars — our calculation, not a SIPRI-published total.
- Is the $2,740.0bn figure the true total for all world military spending?
- No — it's a floor. It covers only the 149 countries in SIPRI's 2025 dataset; North Korea has no series and several other states have gaps, so actual global spending is higher.
- Is the 2025 figure an estimate?
- No. 2025 is reported as an actual figure in this dataset, unlike 2026-2027 figures elsewhere, which are flagged as estimates.
defensebudget.org
Defense spending data, sourced from SIPRI
defensebudget.org tracks military expenditure for 160 countries using the SIPRI Military Expenditure Database. Pages are generated from that dataset and reviewed before publication.