I'm now reading "Understanding Iraq" of William Roe Polk. At page 67, I showed a sentence like this: "Why did the British decide to conquer Iraq?" I want to underline "conquer" and change a misjudgement. I think somebody should understand the differences between "conquer" and "invade". If a place is conquered, All people of this place have confidence in people who conquered. . So they can live safely. This is also valid for enemy forces. But, if a place is invaded, people can't live safely. (example: Iraq) When British supposedly conquered Iraq, people weren't in safety. Just like in Philistine. 15000 Turk soldiers, who fighted against England at Philistine at World War 1, were taken prisioner and after a lot of torture, they were killed via poisoning. Are these England "conquerer" or "invader"? It's your decision.

I think to qualify as a conquerer, you need to have a reasonable amount of control over the territory in which you now call your own.
The people there do not need to like you or recognize you as the leader. If they are subject to your orders, laws and decrees, it's a conquered territory and a conquered set of people.

I don't agree with you. I think a conquerer is who is loved and accepted bye the majority of people. Anyway, at the page of 71 of "Understanding Iraq", author said that English's idea of conquering Iraq was unsuccesful due to not gaining the whole control. Control equals to be loved.

Are you sure you are not confusing conqueror with liberator?

Conquer is the word that includes demographical change in the conquered area. But invade is different. For example Fatih Sultan Mehmed conquered Istanbul in 1453 and make there Turkish city. But US invaded Iraq and did not make there an American city or else. Iraq is still Iraqis so this is what we call "invade". In other words invade is something like military control over a region or state.

Actually to invade is to enter a country in force against the country's will.
To conquer is to secure the area.
"Secure" is a pretty loose term here and there isn't any real set rule on how much security or actual control there needs to be. But a reasonable amount is required to qualify as such.

To The 13th Redneck,
I think You're just right, now. "Conquer" and "invade" differs in country's being willing or unwilling. Thank you for this sharing.

Conquer is by no means a measure of the willingness of the conquered, in fact it is quite often the opposite. What conquer means is to attack an enemy and completely destroy their will/ability to fight AND make the conquered territories part/property of the attacking nation. Invade means to, well, invade, it doesn't have to be permanent or long term, it just simply means the attacking nations had troops inside the defending nation's borders. It doesn't imply any measure of security or completeness. The Germans invaded the Soviet Union but they never conquered it. Romans conquered many of the surrounding peoples but they were rarely loved and certainly not right after the invasion. A people can be conquered without having to accept the new rulers wholly if the conquered were defeated so re-soundly they lack a means to fight back anymore.

Neither term relies on the willingness of the attacked. Invading a nation is typically a prequel to it being conquered. That being said, the mission in Iraq was never to conquer Iraq, it was to invade, remove Saddam from office and establish a quasi-democratic government that would be friendly to the United States.

Thats what I wanted to tell.