Territorial Disputes in the South China Sea
This conflict profile is being developed by IAW analysts
Last update:
Overview
A maritime dispute between China and several Southeast Asian states — the Philippines, Vietnam, Malaysia, Brunei, plus Taiwan — over sovereignty of islands, reefs and waters of the South China Sea, a corridor carrying a third of global maritime trade. Beijing claims nearly the entire sea through the 'nine-dash line', rejected by the 2016 Hague arbitral award that China ignores, and has entrenched its position with militarized artificial islands and a permanent coast guard and maritime militia presence.
The hottest axis is the relationship with the Philippines: incidents at Second Thomas Shoal (Ayungin) and Scarborough combine rammings, water cannon and physical assaults on Filipino personnel, answered by Manila with an 'assertive transparency' strategy and growing military integration with the US — anchored in the Mutual Defense Treaty — Japan and Australia. Negotiation of the ASEAN-China code of conduct, which Manila hopes to conclude during its 2026 chairmanship, advances more slowly than the dispute's militarization.
The China-Philippines dispute escalated again on July 20, 2026 at Second Thomas Shoal (Ayungin), when personnel from a small boat deployed by China Coast Guard cutter 21560 rammed a Philippine Navy rigid inflatable boat near the BRP Sierra Madre and struck Filipino sailors with batons and oars; one Philippine sailor sustained a head injury described by specialized outlets as the worst recorded in the dispute over the feature. The incident, captured on video, broke the relative calm that had held since the July 2024 provisional arrangement on resupply missions to the Sierra Madre. On July 20-21 Manila and Beijing summoned each other's envoys: the Philippine Department of National Defense cited a 'clear pattern of provocative and hostile behavior' and said it was preparing response measures, while China accused the Philippines of 'distorting the facts.' The US State Department condemned the Chinese action on July 20. The clash came hours before a foreign ministers' meeting in Manila, in the year the Philippines chairs ASEAN.
A dispute measured in presence, incidents and exercises — not battlefronts.
Chinese ship-days at Scarborough (H1 2026)
Nearly all of 2025's total (1,099) in just six months; May peak of 216. AMTI/CSIS.
Philippines-China interaction days
First half of 2026, with Philippine patrols up 43%.
Troops in Balikatan 2026
The exercise's largest edition, with Japan as a full participant for the first time.
Philippine sailor injured (Jul 20)
The most serious recorded assault at Second Thomas Shoal; envoys summoned in both capitals.
Who faces whom.
Every actor with what they control and what they are after, and the ties of support and hostility that bind them to the rest. The camps are not assigned by hand: they come from the alliances and enmities recorded in the profile.
Around Philippines
Around China (CCG + maritime militia)
Around Philippines
Around China (CCG + maritime militia)
No declared alignment
Circle size shows relative influence; the amber arc, the share of territory under control. Camps are computed from the alliances and enmities declared in each profile.
Severity index
No severity index: the CSI is a dated measurement and we publish it only where there is weekly monitoring. The profile explains the conflict through context, actors and sources.
Timeline — Key phases
The conflict as process. Each event: context, actors and consequences.
This section will be populated with historical phases
Phase Title - Pending Development
Placeholder text for timeline context
Actors: Key actors to be identified Consequences: Consequences to be documented
Concrete signals the editorial team monitors to anticipate phase changes.
Sierra Madre resupply missions
WorseningThe July 20 incident broke the 2024 arrangement; every mission is now a potential flashpoint.
Build-up at Scarborough
WorseningBuoys, barriers and a platform removed in June: any permanent structure would change the status quo.
ASEAN-China code of conduct
StableManila wants it concluded in 2026 during its chairmanship; July's incident strains the timeline.
Mutual Defense Treaty threshold
StableA Filipino death in an incident with China would directly test the US commitment.
Coverage level
Open conflict · as of Jul 22, 2026
An open conflict we analyse but do not follow day to day. This profile gathers the context, actors and sources verified up to the cut-off date, and publishes no severity index: we do not add new events or recalculate the CSI unless the conflict escalates and we reactivate it. We say so plainly so you know what you are reading.
Last reviewed: Jul 22, 2026.
We publish how complete each profile is. These are the points of our editorial policy that can be checked against the data on file.
6 of 8 checks
- Conflict summary writtenDone
- Timeline with 10 dated events or morePending
- Conflict actors on fileDone
- Conflict status assignedDone
- 8 sources cited or moreDone
- Every published figure with its source and datePending
- Geolocation on fileDone
- Historical and political context writtenDone
Four further policy points — per-claim verification and traceability, naming review and cross-review — are checked by hand and are not part of this count.
Methodology pending: This profile is in initial development. As research is completed, full documentation of data sources, analysis methods, and information limitations will be provided.
Key sources
- USNI News — Philippine Sailor Injured in Violent Clash with China Coast Guard off Second Thomas Shoal
- Asia Maritime Transparency Initiative (CSIS) — Occupational Risk? Chinese Presence Surges at Scarborough Shoal
- USNI News — Balikatan 2026 Was Rehearsal for Defense of the Philippines, Paparo Says
- USNI News — U.S. Coast Guard Patrols Near Scarborough Shoal with Philippine Forces
- Infobae — Filipinas denunció que la guardia costera china golpeó a uno de sus marinos en un atolón disputado del mar de China Meridional
- US Department of State — China's Actions Against Philippine Navy Personnel at Second Thomas Shoal
- US News / Reuters — Philippines, China Summon Each Other's Envoys Over South China Sea Incident
- CSIS Asia Maritime Transparency Initiative
- CSIS AMTI — Island Tracker
- CSIS — Programa de Sudeste Asiático
- International Crisis Group — Mar del Sur de China
- CFR Global Conflict Tracker — Mar del Sur de China
- Corte Permanente de Arbitraje — Filipinas c. China
- Lowy Institute — Mar del Sur de China
- NBR Maritime Awareness Project
- ONU DOALOS — Derecho del Mar (CONVEMAR)
This conflict profile is being developed by International Affairs Watch analysts. As research is completed, all data, scenarios, and indicators will be updated with verified information and in-depth analysis. Users are invited to return once the profile is fully developed.
International Affairs Watch
Related conflicts
Corrections
If you found a wrong figure, a shifted date or a source that no longer says what it said, tell us. We check it and, where warranted, the profile is corrected with the update date left visible.