Just two days after Russian President Vladimir Putin and Ukrainian President Petro Poroshenko had met in Minsk, officials in Kyiv said Russian troops had invaded southeastern Ukraine's and captured several border towns.

NATO also said it had noted a significant escalation in both the level and sophistication of Russia's military interference in Ukraine and released satellite images to prove that these troops are indeed operating on Ukrainian territory.

Meanwhile, European voices calling for tougher sanctions against Moscow are growing.

But Russia does not bat an eye - Moscow denies having invaded Ukraine and says turmoil in the neighboring country was simply a result of Ukraine's domestic problems.

New form of asymmetrical warfare

Russia has been using this perfidious line of attack for months which seems to throw off Western countries. While the Kremlin's official message is a call for peace, war against Ukraine was launched back in March. It all started in Crimea. And since that mission was deemed successful, the Kremlin continued destabilizing eastern Ukraine as Moscow doesn't want to see its neighbor moving closer to Europe.

This new form of asymmetrical warfare - guerilla war 2.0 - makes use of a plethora of tactics: Deploying mercenaries and volunteers who have been trained by professional soldiers or are instructed by them, hidden special operations and a rather elaborate information war.

For a long time, the West simply didn't want to see what was truly going on between Russia and Ukraine. No one in Europe was eager to confront Moscow - especially not in terms of military force. No responsible politician wanted to fuel the situation further by even using the term "war." So far, the Ukrainian heads of state and government also say that their country's troops are formally carrying out an anti-terror operation.

New sanctions

But since separatist leader Alexander Zakharchenko came forward and confirmed that some 3,000 to 4,000 Russian soldiers are indeed fighting in the separatists' ranks - while on leave from their army service, so they say - it finally became clear what has been an open secret for a long time: Russia has been waging a war against Ukraine with the help of separatists. It also gets incredibly hard to hide reports about Russian soldiers who reportedly died in Ukraine.

This blatant Russian meddling in Ukraine forces Europe's hand. However, Ukraine's hopes of a military intervention by European nations or NATO are going to be dashed. The EU will tighten sanctions - and this move will fuel escalations even further.

But Russian leaders have to realize that war and violence are not political instruments in Europe. It's good to know that there are also voices within Russia who no longer shun from speaking up against these kinds of politics.