UKRAINE COUNTEROFFENSIVE DERAILS RUSSIAN DONETSK PINCER PLAN
Ukrainian 3rd Army Corps Commander Andrii Biletskyi reported on October 19 that Operation Vivaldi defeated Russia's northern pincer in the Lyman direction, pushing Ukrainian forces to the Zherebets River. ISW assesses this forced Russian forces into a costlier frontal assault east of Slovyansk and Kramatorsk against prepared Ukrainian defenses.
AT A GLANCE
NEW | UKRAINE | ISW reports Operation Vivaldi defeated Russia's northern pincer near Lyman, forcing a costlier frontal assault approach.
NEW | IRAN | ISW reports Iran may be using more precise, IR-guided weapons to strike engine rooms of commercial ships in Hormuz.
CARRIED FORWARD, OCT 16 | TAIWAN | US and Japan deploy anti-ship missiles to Yonaguni Island during Keen Sword exercises, per the October 16 ISW update.
CARRIED FORWARD, SEP 30 | KOREA | South Korea has not detailed corresponding measures after the DMZ mine incident, per the September 30 ISW update.
WHY OPERATION VIVALDI MATTERS FOR THE DONETSK FRONT
Biletskyi reported that Operation Vivaldi degraded the Russian 144th Motorized Rifle Division to the point it ceased functioning as an organized force. Russia must reconstitute this division before resuming offensive operations toward Lyman, according to the October 20 ISW update.
ISW assesses that Russian forces suffered a net loss of 122 square kilometers between September 1 and October 16, 2026, against roughly 100 square kilometers seized since January 1, 2026. This reflects a broader stall in Russian territorial gains across the frontline this year.
Ukrainian forces continue to face in-motion speed restrictions on Starshield that Beskrestnov says limit counter-drone intercepts against piston engine and jet-powered Geran drones. Zelensky stated on October 19 that these restrictions also undermine frontline logistics and intermediate-range strikes.
Separately, the October 20 ISW update reports that Lavrov and Medvedev reaffirmed Kremlin support for Iran and described the United States as a long-term adversary, despite a US diesel export waiver offered to Russia. ISW assesses this reflects no sincere Kremlin interest in normalizing US relations.
OTHER SIGNALS
IRAN | PRECISION STRIKES TARGET SHIP ENGINE ROOMS IN HORMUZ
ISW report of October 21 · new
The October 21 ISW Iran Update reports that at least five of 23 recorded attacks on vessels in the Strait of Hormuz during the first two weeks of October struck commercial ships' engine rooms, a pattern absent in September. ISW assesses Iran is likely using more precise systems, consistent with its October 5 assessment of improving targeting capability.
ISW assesses Iran is likely employing anti-ship cruise missiles or infrared-guided drones capable of terminal guidance without human control, given strait jamming conditions. Iranian officials reportedly told the Washington Post the regime is focused on driving up oil prices to pressure President Trump before the November 3 midterm elections, as oil exports approach prewar levels.
30-DAY CALLS: 5 of 5 resolved calls held since September 2026. Today's call is below.