MOSCOW — Even before his plane touched down in Finland for a summit meeting with President Trump, President Vladimir V. Putin of Russia, who was widely seen as coming out ahead at the meeting, had notched a victory in the air, the Estonian authorities say.

Estonia — small, vulnerable and at the northeastern rim of the North Atlantic Treaty Organization’s mutual security zone — has long been seen as a test case for the alliance’s willingness to resist Russian military moves.

For more than a decade, Russian military planes have regularly zipped through the edges of NATO airspace over the Baltic Sea off Estonia’s coast, in daring, high-stakes runs that taunt the alliance’s air defenses.

While flying from Russia to Finland on Monday morning, Mr. Putin’s presidential plane entered NATO airspace without clearance over a portion of the Baltic Sea that is often the site of Russian military jet fly-bys, the Estonian military said on Tuesday.