Trump is rattling Europe. Now Harris is going there to try to calm nervous allies

Vice President Harris faces a daunting task this week: try to make the case to European leaders that America is an ally they can count on through thick and thin, despite some recent evidence to the contrary.

In the past week, the Republican front-runner for the presidential race said he would give what sounded like a green light to Russia to attack NATO allies that don't boost military spending. Meanwhile, Republican leaders in the House of Representatives have all but nixed billions of dollars of aid that Ukraine needs to continue its fight against Moscow's invasion.

Since taking office, President Biden has been telling his European counterparts that "America is back" as he has worked to shore up relationships tested by his isolationist predecessor. And Biden had promised U.S. backing to Ukraine for "as long as it takes."

It falls to Harris — Biden's top emissary at this year's Munich Security Conference — to provide assurances, said former Defense Secretary Leon Panetta.

"The key to our ability to be a world leader is not just our military power, not just our diplomatic power, but our credibility, our word," Panetta said in an interview with NPR.

"And if the United States can't back up its word in providing aid to Ukraine, Taiwan, Israel ... because of various conflicts here in Washington, it raises questions," Panetta said.

After Trump's "America First" ethos, Biden pushed for "America's Back"

It's against this backdrop of uncertainty that Harris will take the stage in Munich on Friday to make what's being billed as a major foreign policy speech where she will defend Biden's track record.

Biden faced the same audience in Munich when he first took office — that year, the conference was virtual due to the COVID-19