It would take a matter of weeks. About the same time as Gulf Wars 1 and 2 combined. No army of 1939 would be as well equipped in tanks and aircraft as the Iraqi army was in 1991. And no matter how well trained the soldiers were, their weapons would be almost completely ineffective. For instance, not even the most powerful anti-tank gun in existence at that time -- the German 88 -- would even put a dent in a modern tank.

A few days is all it would take. All the modern army would have to do is start lobbing tatical nukes at the enemy. Their willingness to fight would drop when they realize that they are being slaughtered before they can even get within site of the modern army. *********************** jwmbiz, What do you mean nobody would use nukes? In case you were sleeping through your history classes, we DID use nukes to end that war. It would have been so much better to have had them to use up front before millions of people had died in a conventional war. *********************** "HENRYINMA: We could not have used nuclear weapons in 1939 as they were not developed until 1945" Henry, the question was about a MODERN army fighting in WWII. Implicit in the question is that the modern army would have modern weapon with them. Therefore, they could have nukes. ********************** "RJTRIES: Glen I ran an NBCEE---Division Level. You dont just lob tactical nukes for fun. They have specific purposes--primiarily to disrupt lines of communication. In 1939 Wermecht formations werent ideal for TNF employment becasue of civillian collateral damage" The problem is that you are looking at this with a 21st century mentality. I am looking at it from the perspective of a modern army under the command of the 1940's leadership. In WWII, the leadership was not as concerned about civilian deaths. Berlin was intended to be the first target for a nuclear strike. It was spared that fate only because Germany surrendered before the bombs were ready for use. Hiroshima and Nagasaki were bombed despite that fact that they had large civilian populations. The fire bombing attacks on Japan and Germany killed more civilians than the nuclear strikes did. One bomb dropped on the Imperial Palace in Tokyo, another one dropped on Hitler, and the war would have been over with much fewer deaths than fighting the war with conventional weapons would have. ******************* "KevinW42: I actually agree with jwmbiz, if we used nukes it would spread fallout around Europe wich would still be around today and for yaers to come." Is the fallout from the bombs dropped on Hiroshima and Nagasaki still around and causing problems for the Japanese? No, it is not (http://www.rerf.or.jp/eigo/faqs/faqse.htm#faq12). Therefore, your argument is not relevant.

just the tatics and strategy of modern soilders would dumbfound them. just send a few spec. forces back to do training much like in vietnam and use the men of that time with todays thinkng. not to mention that the men (or ladies) going back in time, would alread know what the enemy had planned. (blitzkrieg- lightning warfare- the concept of striking hard and fast, overwhelming the opposition, uh yes!) and no there is a vast difference in todays Spec. Forces and those of WW2. for instance 90% of the kills in WW2 where done by 10% of the soilders, where as in Vietnam it was more proportionate. the difference was training. in WW2 they used bulls-eye targets while in Vietnam they used Silloettes. the advantage is that using silloettes are a form of mental conditioning. there are many other examples but they are not directly related to the question. peace out!

First of all, it depends on the size of the army. (Yes, size does matter!) However, a lot has changed in 66 years. Tactics, weaponry, and technology have all evolved to a point that would totally overwhelm the equivalent 1939 army. First of all, does the modern army get to take all of its modern equipment with it? Does that mean it gets a supply of its modern weapons? Here are some things to consider if so: 1. Air power - high powered fighters and bombers with radars and advanced electronics. Guided missiles, and precision guided bombs. Air cavalry and gunships. Imagine Gallipoli with a dozen Apache gunship helicopters buzzing overhead... In fact, imagine Gallipoli never happening... the modern army would perform a pre-landing strike with cluster bombs and bunker busters to wipe out the entire enemy defense, and then the landing troops would have just walked over the hill. 2. Sea power - Aircraft carriers, guided missile destroyers, advanced submarines. Factor in also anti-submarine aircraft with Magnetic Anomaly Detectors - these pick up the disturbance in the earth's magnetic field caused by a large metal object. Kiss the U-Boats goodbye. Harpoon missiles. Kiss the enemy ships goodby. Phalanx close defense systems. There would be no chance of airborne attack. 3. Land power - High powered tanks and much more advanced vehicles. Sloped armour with blazer reactive padding. Precision, computer aimed tank turrets. Armour piercing rounds that are designed to punch through the outer armour and explode inside the tank. 4. Special Forces - Yes, the equivalent special forces were good. The modern ones would be better. Better training, better weaponry and items, better tactics. 5. Equipment - man-portable rockets and guided rockets (TOW, Stinger, etc). Highly accurate infantry weaponry. Night vision equipment. Radio and data communication. 6. Tactics - I highly doubt a modern army would let itself get dragged into trench warfare. I'm guessing they would use their non-melee forces to bleed the enemy, then send in the infantry to occupy the ground. Trenches wouldn't last too long under a haze of cluster bombs. If the modern army cannot take any equipment with them, then I guess it will come down to the better trained, better disciplined army. In short, a fully equipped modern army could pull the wolf's teeth in less than a month of sustained strikes. The 1939 army wouldn't know what hit it. However, a modern army with period equipment would have to fight just as hard as the original army did, and may even do worse.

A month or 2, if they had modern weapons.