Threatening economic sanctions and penalties for military advances in Crimea, the United States and six other Western nations suspended plans for a summit in Russia this summer and condemned the actions of Russian President Vladimir Putin against Ukraine, rushing to find some way to stop the Russians from a bolder military move in that Eastern European nation.

"We are united in supporting Ukraine’s sovereignty and territorial integrity, and its right to choose its own future," read a Sunday statement issued by the White House on behalf of the G-7 nations.

"We commit ourselves to support Ukraine in its efforts to restore unity, stability, and political and economic health to the country," the statement added.

Secretary of State John Kerry announced on Sunday that he would fly to Kiev for talks on Tuesday with Ukranian leaders, a move one Senator labeled a 'very positive step.'

"I hope he's going to go on to Russia and talk to Putin," said Sen. Saxby Chambliss (R-GA), the top Republican on the Senate Intelligence Committee.

Chambliss described a weekend of briefings by both the White House and intelligence community officials for lawmakers, which still left Washington unsure what Putin would do next.

"My guess is Putin pushes up to the brink and he hopes that Ukraine folds," Chambliss told me Sunday night.

The fast-moving events sparked a heated back and forth between Republicans and Democrats on who was to blame for the current situation in Ukraine, which some experts labeled the biggest threat to peace and stability in Europe since the 1968 Soviet invasion of Czechoslovakia.

"When the United States is weak, freedom around the world suffers and we are witnessing this first hand today in the Ukraine," said Rep. Mike Turner (R-OH), a stern critic of Obama Administration defense policies.

At the White House, a senior administration official bristled at the suggestion that President Obama's policies had led to the Ukraine crisis.

"We in this administration have not made it a practice to look into Vladimir Putin's soul," the official said, taking a direct jab at President Bush, who thought he had figured out a way to work with Putin, but watched that dissolve as Russia invaded parts of Georgia in 2008, ignoring American and European protests that sound very similar to those about Ukraine in recent days.

But with every flash of news from Ukraine and Crimea, there was another zinger being lobbed over who had committed bigger foreign policy blunders vis-a-vis Putin and the Russians.

"What we are seeing is the inevitable result of the Obama administration’s systematic retreat from leadership on the world stage," a former senior national security official told me Sunday. "In this case the Ukrainian people stand to pay the price."

Obama Administration officials said the U.S. and European leaders were focusing on possible economic sanctions against the Russians, as well as getting international economic aid to Ukraine to help that nation rebuild its own fortunes.

But it wasn't clear whether that future would be without the Crimean Peninsula - and maybe other areas inside Ukraine - if Putin pushes forward with military action.

"He could run over Ukraine," Sen. Chambliss said, before any sanctions could have an impact.

The issue is certain to come up Monday in a White House meeting between Vice President Biden and the visiting Prime Minister of Moldova, a country on Ukraine's southwest border that has been at odds with Russia for years over a breakaway province known as Transdniester, which has Russian military ties.