In June 2023, NATO, including the U.S. and Sweden, conducted Baltic Sea military exercises focusing on disrupting Russian espionage and sabotage threats in contested waters near Sweden.

Military & Paramilitary OperationsConventional Military PressureSnap military exercises & drills

AggressorDefense

Summary

Amid rising concerns of Russian hybrid warfare, including suspected sabotage and airspace violations near NATO countries bordering the Baltic Sea, NATO allies conducted a military exercise in late June 2023. The exercise took place mainly in the Baltic Sea and from Stockholm harbor, Sweden, involving a German submarine acting as a pseudo-enemy. U.S. forces participated via spy plane flights overhead, while Sweden deployed its stealth warship HMS Helsingborg searching for the enemy sub. NATO officials emphasized the threat of Russian covert activity such as undersea cable sabotage and espionage. Sweden, a new NATO member since 2022 following Russia’s invasion of Ukraine, and other Baltic bordering allies like Finland, Poland, and Germany have boosted defense spending amid this tense gray zone between peace and war, reminiscent of Cold War-era tensions. The Kremlin has asserted it is at war with NATO, citing NATO’s support for Ukraine. The exercise highlighted NATO’s defensive posture to counter interconnected threats posed by Russia in northern Europe.

Classification

Confidence: High

Classification as aggressor event is supported by credible statements describing suspected Russian hybrid warfare activities including sabotage, airspace violations, and espionage in the Baltic Sea region. Classification as defense preparation event is supported by detailed reporting of NATO-led joint military exercises including U.S. and Swedish participation aimed at countering these threats and boosting defense postures by Baltic allies.

Source URL

https://cbsnews.com/news/us-nato-allies-russia-hybrid-warfare-europe-cbs-sees-baltic-sea-exercise

Open source

Provenance

Publisher: extension
Submitted: Feb 1, 2026, 00:14 UTC
Last updated: Nov 8, 2026, 21:46 UTC
Event time: Jun 25, 2023, 00:00 UTC

Published as a Defense Preparations signal with a public source and reviewer-approved assessment bands. See the methodology for how records are assessed.

Raw record

{
  "id": "d6e8ca9c-fa79-45d7-9352-9e2611ff7981",
  "url": "https://cbsnews.com/news/us-nato-allies-russia-hybrid-warfare-europe-cbs-sees-baltic-sea-exercise",
  "source": "extension",
  "status": "approved",
  "category": "Military & Paramilitary Operations",
  "subcategory": "Conventional Military Pressure",
  "incident_type": "Snap military exercises & drills",
  "country": "Sweden",
  "source_reliability": "C",
  "info_credibility": "3",
  "tags": [
    "NATO",
    "Russia",
    "Sweden",
    "Baltic Sea",
    "Hybrid Warfare",
    "Military Exercises",
    "Submarine",
    "Espionage",
    "Sabotage",
    "Undersea Cables",
    "drone activity",
    "U.S. Navy",
    "baltic sea region"
  ],
  "nodes": [
    "Node 1: Borders"
  ],
  "countries": [],
  "where_text": "Maritime",
  "headline": null,
  "description": "In June 2023, NATO, including the United States, Germany, Sweden, Finland, Poland, and Germany, conducted a joint military exercise in the Baltic Sea. The drill focused on hunting a German submarine playing the role of a hostile enemy conducting covert espionage and sabotage, reflecting concerns over Russian hybrid warfare tactics such as airspace violations, drone sightings near military bases, and undersea cable sabotage. The exercise was staged from Stockholm's harbor with use of stealth vessels like Sweden's HMS Helsingborg and spy planes from the U.S. Navy. NATO officials warned that adversary threats in the Baltic region pose interconnected risks globally. Baltic NATO members have significantly increased defense spending following Russia’s 2022 invasion of Ukraine. Swedish submarine flotilla commander Paula Wallenburg described the current situation as close to Cold War tension levels, emphasizing the seriousness of regional security concerns.",
  "summary_short": "In June 2023, NATO, including the U.S. and Sweden, conducted Baltic Sea military exercises focusing on disrupting Russian espionage and sabotage threats in contested waters near Sweden.",
  "summary_extended": "Amid rising concerns of Russian hybrid warfare, including suspected sabotage and airspace violations near NATO countries bordering the Baltic Sea, NATO allies conducted a military exercise in late June 2023. The exercise took place mainly in the Baltic Sea and from Stockholm harbor, Sweden, involving a German submarine acting as a pseudo-enemy. U.S. forces participated via spy plane flights overhead, while Sweden deployed its stealth warship HMS Helsingborg searching for the enemy sub. NATO officials emphasized the threat of Russian covert activity such as undersea cable sabotage and espionage. Sweden, a new NATO member since 2022 following Russia’s invasion of Ukraine, and other Baltic bordering allies like Finland, Poland, and Germany have boosted defense spending amid this tense gray zone between peace and war, reminiscent of Cold War-era tensions. The Kremlin has asserted it is at war with NATO, citing NATO’s support for Ukraine. The exercise highlighted NATO’s defensive posture to counter interconnected threats posed by Russia in northern Europe.",
  "actor_primary": "Russia",
  "target_primary": null,
  "location_text": "Baltic Sea, Stockholm harbor, Sweden",
  "location_region": null,
  "location_coordinates_lat": null,
  "location_coordinates_lon": null,
  "location_precision": "Regional",
  "is_aggressor_signal": true,
  "signal_type": "DEFENSE_PREP_SIGNAL",
  "is_hybrid_war_signal": true,
  "classification_complete": true,
  "hybrid_signal_complete": true,
  "classification_confidence": "High",
  "classification_rationale": "Classification as aggressor event is supported by credible statements describing suspected Russian hybrid warfare activities including sabotage, airspace violations, and espionage in the Baltic Sea region. Classification as defense preparation event is supported by detailed reporting of NATO-led joint military exercises including U.S. and Swedish participation aimed at countering these threats and boosting defense postures by Baltic allies.",
  "event_time_utc": "2023-06-25T00:00:00.000Z",
  "end_time_utc": null,
  "event_time_confidence": "unknown",
  "created_at": "2026-02-01T00:14:47.866Z",
  "updated_at": "2026-11-08T21:46:15.049Z",
  "reliability_band": "strong",
  "location_precision_band": "regional",
  "time_precision_band": "unknown",
  "severity_band": "moderate",
  "attribution_confidence_band": "high",
  "attribution_basis": "single_source"
}

Public assessmentReliability: StrongSeverity: ModerateAttribution: HighSingle sourceTime: UnknownLocation: Regional

Source reliability

Info credibility

Event time

Jun 25, 2023, 00:00 UTC

Event time confidence

unknown

Location

Baltic Sea, Stockholm harbor, Sweden

Primary actor

Russia

Country

Sweden

Tags

NATO, Russia, Sweden, Baltic Sea, Hybrid Warfare, Military Exercises, Submarine, Espionage, Sabotage, Undersea Cables, drone activity, U.S. Navy, baltic sea region

Nodes

Node 1: Borders

Loading signal...

{ "id": "d6e8ca9c-fa79-45d7-9352-9e2611ff7981", "url": "https://cbsnews.com/news/us-nato-allies-russia-hybrid-warfare-europe-cbs-sees-baltic-sea-exercise", "source": "extension", "status": "approved", "category": "Military & Paramilitary Operations", "subcategory": "Conventional Military Pressure", "incident_type": "Snap military exercises & drills", "country": "Sweden", "source_reliability": "C", "info_credibility": "3", "tags": [ "NATO", "Russia", "Sweden", "Baltic Sea", "Hybrid Warfare", "Military Exercises", "Submarine", "Espionage", "Sabotage", "Undersea Cables", "drone activity", "U.S. Navy", "baltic sea region" ], "nodes": [ "Node 1: Borders" ], "countries": [], "where_text": "Maritime", "headline": null, "description": "In June 2023, NATO, including the United States, Germany, Sweden, Finland, Poland, and Germany, conducted a joint military exercise in the Baltic Sea. The drill focused on hunting a German submarine playing the role of a hostile enemy conducting covert espionage and sabotage, reflecting concerns over Russian hybrid warfare tactics such as airspace violations, drone sightings near military bases, and undersea cable sabotage. The exercise was staged from Stockholm's harbor with use of stealth vessels like Sweden's HMS Helsingborg and spy planes from the U.S. Navy. NATO officials warned that adversary threats in the Baltic region pose interconnected risks globally. Baltic NATO members have significantly increased defense spending following Russia’s 2022 invasion of Ukraine. Swedish submarine flotilla commander Paula Wallenburg described the current situation as close to Cold War tension levels, emphasizing the seriousness of regional security concerns.", "summary_short": "In June 2023, NATO, including the U.S. and Sweden, conducted Baltic Sea military exercises focusing on disrupting Russian espionage and sabotage threats in contested waters near Sweden.", "summary_extended": "Amid rising concerns of Russian hybrid warfare, including suspected sabotage and airspace violations near NATO countries bordering the Baltic Sea, NATO allies conducted a military exercise in late June 2023. The exercise took place mainly in the Baltic Sea and from Stockholm harbor, Sweden, involving a German submarine acting as a pseudo-enemy. U.S. forces participated via spy plane flights overhead, while Sweden deployed its stealth warship HMS Helsingborg searching for the enemy sub. NATO officials emphasized the threat of Russian covert activity such as undersea cable sabotage and espionage. Sweden, a new NATO member since 2022 following Russia’s invasion of Ukraine, and other Baltic bordering allies like Finland, Poland, and Germany have boosted defense spending amid this tense gray zone between peace and war, reminiscent of Cold War-era tensions. The Kremlin has asserted it is at war with NATO, citing NATO’s support for Ukraine. The exercise highlighted NATO’s defensive posture to counter interconnected threats posed by Russia in northern Europe.", "actor_primary": "Russia", "target_primary": null, "location_text": "Baltic Sea, Stockholm harbor, Sweden", "location_region": null, "location_coordinates_lat": null, "location_coordinates_lon": null, "location_precision": "Regional", "is_aggressor_signal": true, "signal_type": "DEFENSE_PREP_SIGNAL", "is_hybrid_war_signal": true, "classification_complete": true, "hybrid_signal_complete": true, "classification_confidence": "High", "classification_rationale": "Classification as aggressor event is supported by credible statements describing suspected Russian hybrid warfare activities including sabotage, airspace violations, and espionage in the Baltic Sea region. Classification as defense preparation event is supported by detailed reporting of NATO-led joint military exercises including U.S. and Swedish participation aimed at countering these threats and boosting defense postures by Baltic allies.", "event_time_utc": "2023-06-25T00:00:00.000Z", "end_time_utc": null, "event_time_confidence": "unknown", "created_at": "2026-02-01T00:14:47.866Z", "updated_at": "2026-11-08T21:46:15.049Z", "reliability_band": "strong", "location_precision_band": "regional", "time_precision_band": "unknown", "severity_band": "moderate", "attribution_confidence_band": "high", "attribution_basis": "single_source" }