D-Day was the largest amphibious invasion in history — and likely the last. Here's why.

• D-Day on June 6, 1944 was a gargantuan feat. Is it the last invasion of its kind?
• In World War II, the best way to stop an amphibious invasion was before troops reached the beach.
• Modern weapons and surveillance systems give a defender more power to accomplish that.

D-Day is more than the largest amphibious invasion in history. Even 80 years after the battle, it still resonates as an epic of courage, endurance, and prodigious effort.

But was D-Day the last invasion of its kind? Could such immense resources be mustered again in a modern-day version of "Saving Private Ryan"-style landings?