Announcer: Starting right now on ABC "This week" -- developing this morning, stunner in the skies. A Russian military plane narrowly avoids a collision with a passenger jet. What has officials so... See More
Announcer: Starting right now on ABC "This week" -- developing this morning, stunner in the skies. A Russian military plane narrowly avoids a collision with a passenger jet. What has officials so alarmed. The cia and torture. Shocking new details from the explosive investigation. 2016 showdown. Could new moves preview a battle between Hillary Clinton and Elizabeth Warren? And Jeb bush dropping his biggest hint yet. I'm going to make up my mind in short order And the pilgrimage, wounded American vets go overseas, looking for a miracle. Announcer: From ABC news, "This week" with George stephanopoulos, begins now. Good morning. I'm Martha Raddatz, and we're tracking stories developing on several fronts, including nationwide protests against police brutality. Saturday, tens of thousands hit the streets in New York and Washington. The mother of Michael brown taking part. Events were mostly peaceful. Although 23 people were arrested in Boston. But also, breaking this morning, alarms raised after a mid-air scare involving a Russian military jet, a very close call putting a passenger plane at risk, the latest sign of that high-stakes tension growing between Russia and the west. ABC's terry Moran on how it happened. Reporter: Russian military jets like these have been probing deeper and deeper into nato air space over Europe in recent months and yesterday, a near-disaster. 11:15 A.M. Local time, a flight over the baltic seas gets an urgent warning from Swedish air traffic control. That unidentified traffic a Russian military jet, flying with its transponder switched off. Making it almost invisible to commercial traffic. The scandinavians can't see the Russian in the skies and seconds later, a mid-air collision is just averted. Swedish officials reacted with fury, the defense minister declaring -- "This is serious, this is inappropriate." And it's part of a grimly, relentless pattern. These pictures show a close encounter less than 100 feet between nato interceptors and Russian jets over the baltic seas just last week. In October, this grainy photo and advanced sonar data, to scour the waters off Stockholm. The Russians deny everything. But the Swedes and nato aren't buying it. They said Russia practiced a practice bombing run over Stockholm last year. It's all part of Moscow's message to Europe and the U.S., we're back and we can pierce your defenses. Martha? Thanks, terry, that sounds dangerous. Let's take this on with our ABC contributor and former state department official, Steven ganyard. Let's start from that vantage point. How dangerous was this? Very dangerous. Any time you're flying airplanes without the transponder on in a very crowded commercial air space it's dangerous. Because air traffic controllers can't see it. Remember, in the previous incident, we came within 300 feet of Russian airplane and another aircraft, so it's very dangerous. Lot of these intercepts lately, a Dutch f-16 that intercepted a Russian plane. Take us through that. An unprecedented Numbers of sorties coming out of Russia, it's like back to the future. You got to launch airplanes out of nato air bases, I.D. Them -- They fly right next to the airplane. We saw a terrific video of that. It's really back to the future. But all of this brings us back to the tension in Ukraine, so, why do they send the jets there and what does this do to add to that tension? Mr. Putin is doing the best he can to play a weak hand. By going up in the baltics and creating tension up in the baltics, he deflects public opinion of that part of the world. He pins down nato forces. Meantime, he continues to build this greater Russia. It also seems like an incredibly dangerous time going forward. It's a very bad time for Russia, they're in an economic crisis. What is your prediction going forward? It's a dangerous time. The ruble tanked 40%. The Russian economy is totally dependent for revenues from oil. Sanctions are biting. This is a very dangerous time, Russia is wounded. We could see Mr. Putin do something that would jack the price of oil up by manufacturing some sort of incident somewhere else. Just one more thing to keep our eyes on. Thanks very much for joining us, Steve.
This transcript has been automatically generated and may not be 100% accurate.