WASHINGTON — When Secretary of State Mike Pompeo, in a curse-laden tirade to a reporter on Friday, asked, “Do you think Americans care about Ukraine?” he was getting at an essential element of President Trump’s defense in the impeachment trial. White House officials are convinced that Americans are indifferent to what happens in the struggling former Soviet republic, and they may well be right.

But the impeachment trial is about more than the fate of Ukraine — and whether Mr. Trump sold it out for a “domestic political errand,” as his former adviser, Fiona Hill, put it so bitingly. To Democrats, it’s about a president who undercut his own administration’s stated goal of pushing back hard against Vladimir V. Putin’s Russia — the geopolitical challenge of a new, very different Cold War.

It is one of those cases where the geography of the debate shapes the politics of the argument.

As long as the president’s lawyers can focus the debate on the narrower question of Ukraine, they can argue that the charges against the president focus on a foreign policy sideshow: how the president uses the spigot of American aid and attention to mold another country’s behavior.

“They basically said, ‘Let’s cancel an election over a meeting with the Ukraine,’” Mr. Trump’s White House counsel, Pat A. Cipollone, said on Saturday, characterizing the Democrats’ arguments as he opened the president’s defense. Mr. Cipollone made the case that the Democrats are seeking to undo Mr. Trump’s 2016 victory or fear that they cannot beat him in 2020.