TALLINN, Estonia -- They may look like soldiers, but they’re actually ordinary men and women with day jobs who volunteer in the Estonian Defence League, a kind of citizen’s militia.

There are more than 13,000 of them, a civilian resistance force ready to rise up if Estonia were attacked.

Right now, they believe their aggressive neighbor to the east -- Russia -- is enemy number one, especially after its invasion of Ukraine.

Estonia has a professional military too; It was on display in this weekend’s Independence Day parade.

American soldiers march in Estonia’s Independence Day parade CBS News

This small country spends big on defense. It’s a fully paid-up member of NATO, and that buys it powerful friends.

Estonian Defense Minister Margus Tsahkna CBS News

This year, U.S. soldiers deployed to Estonia were part of the parade, and for the first time they brought tanks.

American tanks on the streets of Estonia’s capital send a powerful message to the people; that the U.S. will stand by its NATO allies. They also send a clear signal to the Kremlin.

That signal: a Russian attack on Estonia backed by NATO would be dangerous.

“We are sending the message to Russia very clearly that” we are able to speak the same language as Mr. Putin does, and it’s language that we are ready to fight,” said Defense Minister Margus Tsahkna.

And staying ready means constant training.

On Saturday near the town of Voru, local women of the Defense League were learning to use GPS equipment.

Members of the Estonian Defense League prepare for an annual excercise CBS News

For Ruth Maadla, it’s about learning new skills. She doesn’t really expect the Russian to invade, but “ I think it’s good to have the message,” she said.

That message to Russia is loud and clear: Estonia is spending record amounts on its military, and the Defence League had never had more volunteers.