the second suspected ukrainian attack in a week russia s military called it sabotage ukraine s military didn t take credit for it publicly but said it makes them happy. in moscow they said u.s. weapons fueled the war saying it is lengthening the conflict president zelenskyy accuses putin of nuclear blackmail for weeks ukraine s leaders have been promising a counter offensive to drive russian forces out of the south. reporter: who right now is winning the war? there have been ebbs and flows in the war i would say the ukrainians have seized the initiative. reporter: today we spoke with alexander vinman in kyiv he s the ukrainian american white house official who blew the whistle on the phone call with zelenskyy it was my duty to report. reporter: and took center stage in trump s first impeachment. we could have helped make this a short war.