Some criticize Obama's phone-based diplomacy

So far, Barack Obama's summer has been full of international issues.

Based on an analysis of his phone logs, the president is spending more time talking with foreign leaders than he has in months. But just how effective is telephone diplomacy?

President Obama made at least four calls in July to German Chancellor Angela Merkel, three to Israeli Prime Minister Benjamin Netanyahu, and the latest call in a busy month was a video conference Monday with four European leaders to discuss possible new sanctions on Russia, CBS News correspondent Bill Plante reports.

"This was, I think, by our count, about the 50th call or video conference the president has had with his European counterparts since the beginning of this crisis," said Deputy National Security Advisor Tony Blinken.

Despite mounting tensions on the border with Ukraine, the White House pointed to elections and an agreement with Europe as evidence diplomacy is working.

"None of these things just happened," Blinken said. "They were the result of a major sustained effort by the president to lead the international community."

According to an analysis of public readouts by USA Today, Monday's call was the 500th of Obama's presidency, with more than two dozen coming just this month.

White House reporter Gregory Korte views Obama's foreign relations as need-based.

"They tend to come in bunches," Korte said. "Obama, unlike some of his predecessors, doesn't spend a whole lot of time maintaining relationships. He is more likely to call in a time of crisis."

Public announcements help officials highlight the president's engagement even while away from Washington.

"He has called in a lot this month," Korte said. "He has been to 12 fundraisers and political events and actually the calls tend to come on those days where he is traveling."

But presidential management by phone doesn't satisfy critics. During a recent political trip to California, Republicans on Capitol Hill said the president should have stayed focused on crises at home and abroad.

"It is scandalous that the president has more time to be fundraiser-in-chief than he does to do his basic job as commander-in-chief," Texas Senator Ted Cruz said Thursday.

The White House response is twofold: They say the president can do his job wherever he is, and they defend diplomacy by phone as an important tool, saying that after the Ukraine crisis, constant communication with foreign leaders has helped keep the spotlight on the actions of Russian President Vladimir Putin.