I hate to break this to some of y'all... but countries with a history of war always have quite a few defeats to go along with their victories, and most had the best something or other at some point in time.
Custer tried to defend the bottom of a hole.
The Brits sent an army, with some more units picked up from their new American colonies, against the French & Indians.. and were decimated.
After gaining independence, America attempted the same movement, and aside from building some forts, met the exact same fate as the British.
A Brit infantry square was broken by sword wielding dervishes in Egypt.
The Charge of the Light Brigade didn't make it very far.
The Maginot Line... which, technically, worked as intended, cost the French their country and thousands of british lives.
The Spanish lost their Armada.
The French were driven out of Haiti by an army of their ex-slaves.
The Brits lost an entire army, the baggage train, and all their hanger-on's retreating from Asia back to the Middle East. The survivors you could count on 1 hand.
The Mexicans lost Texas because their general decided to take a nap and didn't properly deploy sentries. 3 minutes later his command was destroyed, most of his officers were dead, and he was running to go hide naked in a well.
The British had to use concentration camps to defeat the Boers.
America politicans tried to run the Vietnam conflict.. and well.. we see what happened there.
The Clinton era deployments were riddled with problems, and ended up giving us the movie Blackhawk Down and grainy pics of a shotdown F-117.
With the right leadership and the right tactics, anybody can beat anybody at any given time. Unfortunately, the best, brightest, bravest, and most honest rarely make it into positions were they can make a difference.