In a move that could dramatically spike international tensions and escalate the conflict in eastern Ukraine, the Prime Minister of the Ukraine government in Kiev on Friday submitted legislation to Parliament declaring intention to join the western military alliance of NATO and longer-term ambitions to actually join the European Union.

Prime Minister Arseny Yatsenyuk submitted the proposal on Friday just ahead of a NATO emergency meeting held in Brussels to discuss the ongoing crisis in Ukraine.

Following that meeting, NATO’s Secretary-General Anders Fogh Rasmussen emerged to say NATO would “fully respect” Ukraine’s effort to join the alliance.

In comments on Thursday, President Obama chastized Russia for its behavior in Ukraine, blaming President Vladimir Putin for the continued resistance shown by armed rebels in the regions of Luhansk and Donetsk who have resisted submission to the government in Kiev which came to power in a coup earlier this year. “The  violence [of the pro-Russian separatists] is encouraged by Russia,” the president charged. “The separatists are trained by Russia.  They are armed by Russia.  They are funded by Russia.  Russia has deliberately and repeatedly violated the sovereignty and territorial integrity of Ukraine.”

Responding to such accusations on Friday, Putin dismissed the idea that Russia was solely to blame for the current situation as he praised the resistance fighters in eastern Ukraine and said the Kiev government–backed by western power–was guilty of killing civilians as the Ukraine Army has conducted mass shelling against rebel-held cities. According to the Moscow Times, Putin said the Russian takeover of Crimea earlier this year was essential to save a largely Russian-speaking population from Ukrainian government violence and that continued fighting in eastern Ukraine, where pro-Russian separatists launched an uprising in April, was the result of a refusal by Kiev to negotiate.

“We don’t want [any large-scale conflicts] and don’t plan on it,” Putin said. “But naturally, we should always be ready to repel any aggression toward Russia.”

He continued, “Russia’s partners… should understand it’s best not to mess with us.” Then added, “I want to remind you that Russia is one of the leading nuclear powers.”

In his remarks, Obama made direct reference an upcoming NATO summit—scheduled for next month in the UK—where he said the U.S. and other alliance members would reaffirm their “unwavering commitment” to Ukraine.

Though not well understood by many in the west, a move by Ukraine to join NATO  actually strikes at the heart of the current crisis and experts warn that further moves by the U.S. or European leaders to encourage Kiev’s official alignment with either NATO or the EU could have significant and disastrous consequences.

Writing at FireDogLake, DS Wright called the effort to join NATO by Prime Minister Yatsenyuk—a favorite of western leaders—a “potentially catastrophic move,” writing:

Speaking with Democracy Now! on Friday morning, journalist Jonathan Steele, former Moscow bureau chief for the Guardian newspaper, argued the most important aspect to understand about the underlying political dynamics is that “Russia is trying to prevent Ukraine joining NATO.”

To explain the reasoning behind Russia’s thinking, Steele explained, “Imagine what would happen if Canada or Mexico decided to join an anti-U.S. alliance? Obviously, the U.S. would be concerned. Russia has legitimate concerns about the expansion of NATO. We’ve already heard just in the other day the Secretary-General of NATO Anders Fogh Rasmussen was saying that NATO is now going to preposition stocks in Eastern Europe, and bring equipment in and have bases there. It is only further provocation to Moscow.”

Steele was referring to comments made by Rasmussen earlier this week in which he said NATO is planning to create a military “spearhead” in former Eastern Bloc countries as a way to counter Moscow.