What if: German invasion of Iceland (Operation Ikarus)

[lordroel]

What if: German invasion of Iceland (Operation Ikarus)

Operation Ikarus (German: Unternehmen Ikarus or Fall Ikarus) was a World War II German plan to invade Iceland because Germany recognized Iceland’s strategic significance. If the island could somehow be seized, air units based there could wreak havoc on the shipping lanes between Britain and the Western Hemisphere. Naval forces, especially submarines, could also sortie from the island to attack convoy routes.

Getting there would be the problem. The Kriegsmarine had pulled off an extraordinary feat by seizing Norway in the teeth of British naval supremacy. Even then, the German fleet lost many valuable warships. But Fall Weserübung, the invasion of Norway, took place with considerable Air Force assistance. Other than a few long-range reconnaissance squadrons, any air units sent to Iceland would require naval transport to get there. And their entire ground echelon, plus fuel and other supplies, would have to come by ship as well.

Despite these difficulties, the German Navy put together a plan called Fall Ikarus. The planning staff concluded that the operation itself would be feasible, especially if executed late in the year (with long nights to help cover naval movements). However, it saw little advantage to the move. Since re-supply convoys would be difficult if not impossible to bring through to the island, the British would eventually re-capture Iceland and any troops sent there would be lost.


Liners Europa (left) and Bremen seen at Bremerhaven in 1930.

Overruling this seemingly crucial objection, Hitler ordered the navy to begin long-term preparations to execute the operation. In this plan, a provisional brigade of mountain troops drawn from the 3rd Mountain Division then stationed in northern Norway would make a quick dash to Reykjavik. The big liners Bremen and Europa had already begun a rapid refit for use as fast troop transports for Operation Naumburg, the reinforcement of 3rd Mountain Division by sea during the struggle for Narvik in the spring of 1940. They had even been fitted to bring a dozen tanks each and unload them by lighter, and these would be available for Ikarus as well.

The two liners would carry the brigade, which would be short of heavy weapons. The jägers would secure the harbor at Reykjavik and that at Hvalfjord nearby, defeating any British forces they found. Whatever heavy warships then available would escort the liners, but the battleships or cruisers would only remain briefly to provide a quick bombardment – the German Navy had no protocol for actual coordinated fire support. Ikarus would depend on surprise and speed.

At the core of the Ikarus force (which apparently never received a designation) would be the 139th Mountain Regiment. The division would add bicycle, engineer and pack artillery elements as well, with a tank company drawn from the 40th Tank Battalion to round out the force. Thus the German brigade would be very similar in strength to the American marine brigade that might have awaited it.

Germany’s sneak attack on the Soviet Union in June 1941 – launched on the same day the American Marines arrived in Iceland – brought an end to the unwieldy plan. German attacks on Atlantic convoys would have to depend on bases in Norway and France instead, and Iceland avoided the devastation of ground combat.

[doug181]

Why take something impossible to supply?

[stevep]

Jul 22, 2017 16:55:03 GMT doug181 said:

Why take something impossible to supply?

  Fully agree.  Its a great move to get more of the KM sunk trying to take and then hold Iceland.  Not to mention the impact on public opinion in the US with the Nazis getting that much closer to the Americas.  Its a win-win situation, for Britain and the pro-intervention Americans.

[lordroel]

Jul 22, 2017 17:50:54 GMT stevep said:

Jul 22, 2017 16:55:03 GMT doug181 said:

Why take something impossible to supply?

  Fully agree.  Its a great move to get more of the KM sunk trying to take and then hold Iceland.  Not to mention the impact on public opinion in the US with the Nazis getting that much closer to the Americas.  Its a win-win situation, for Britain and the pro-intervention Americans.

Well it only one of many plans Hitler toughed of, invading Iceland can be put on the same impossible list as invading the United Kingdom and Malta.

[eurowatch]

Jul 22, 2017 20:20:02 GMT lordroel said:

Jul 22, 2017 17:50:54 GMT stevep said:

  Fully agree.  Its a great move to get more of the KM sunk trying to take and then hold Iceland.  Not to mention the impact on public opinion in the US with the Nazis getting that much closer to the Americas.  Its a win-win situation, for Britain and the pro-intervention Americans.

Well it only one of many plans Hitler toughed of, invading Iceland can be put on the same impossible list as invading the United Kingdom and Malta.

The United Kingdom yes, Malta not so much. 

[stevep]

Jul 22, 2017 21:13:12 GMT eurowatch said:

Jul 22, 2017 20:20:02 GMT lordroel said:

Well it only one of many plans Hitler toughed of, invading Iceland can be put on the same impossible list as invading the United Kingdom and Malta.

The United Kingdom yes, Malta not so much. 

  Agreed.  Especially in the early days of the conflict in the Med Malta was very weakly defended.  Think of Faith, Hope and Charity for instance!  If Hitler had been willing, especially committing the paras to an attack on Malta rather than Crete it would have been very difficult to hold.  Mind you there are differing views on how important it was to the war in the Med. 

[lordroel]

Jul 23, 2017 12:23:07 GMT stevep said:

Jul 22, 2017 21:13:12 GMT eurowatch said:

The United Kingdom yes, Malta not so much. 

  Agreed.  Especially in the early days of the conflict in the Med Malta was very weakly defended.  Think of Faith, Hope and Charity for instance!  If Hitler had been willing, especially committing the paras to an attack on Malta rather than Crete it would have been very difficult to hold.  Mind you there are differing views on how important it was to the war in the Med. 

But holding Iceland, even for a while would benefit the Germans, ore am i wrong.

[eurowatch]

Jul 23, 2017 14:27:34 GMT lordroel said:

Jul 23, 2017 12:23:07 GMT stevep said:

  Agreed.  Especially in the early days of the conflict in the Med Malta was very weakly defended.  Think of Faith, Hope and Charity for instance!  If Hitler had been willing, especially committing the paras to an attack on Malta rather than Crete it would have been very difficult to hold.  Mind you there are differing views on how important it was to the war in the Med. 

But holding Iceland, even for a while would benefit the Germans, ore am i wrong.

Yes, but considering how much they could potentially lose the potential gains are not worth enough. 

[lordroel]

Jul 23, 2017 15:13:03 GMT eurowatch said:

Jul 23, 2017 14:27:34 GMT lordroel said:

But holding Iceland, even for a while would benefit the Germans, ore am i wrong.

Yes, but considering how much they could potentially lose the potential gains are not worth enough. 

Well that was true for Crete as well i think.

[stevep]

Jul 23, 2017 14:27:34 GMT lordroel said:

Jul 23, 2017 12:23:07 GMT stevep said:

  Agreed.  Especially in the early days of the conflict in the Med Malta was very weakly defended.  Think of Faith, Hope and Charity for instance!  If Hitler had been willing, especially committing the paras to an attack on Malta rather than Crete it would have been very difficult to hold.  Mind you there are differing views on how important it was to the war in the Med. 

But holding Iceland, even for a while would benefit the Germans, ore am i wrong.

  Militarily it stops the allies basing units there, especially LRPA for operations against the U boats.  However I'm uncertain whether they would be able to operate forces from there themselves because of the difficulty of getting supplies there.

  Whether those bonuses would outweigh the impact on US public opinion or the losses occurred in taking and then trying to hold Iceland would be the key points I believe.

  I suspect the most likely result however would be that the invasion force is likely to be intercepted and possibly suffer heavy losses on the way.  Not to mention is this invasion before or after the island is garrisoned by Britain after the surrender of Denmark? - Actually checking Operation Fox, en.wikipedia.org/wiki/Invasion_of_Iceland, was as early as 10th May 1940 so any invading force would be opposed by at least the 900+ Royal Marines in the initial invasion if nothing else. 

[lordroel]

Jul 23, 2017 21:12:03 GMT stevep said:

  I suspect the most likely result however would be that the invasion force is likely to be intercepted and possibly suffer heavy losses on the way.  Not to mention is this invasion before or after the island is garrisoned by Britain after the surrender of Denmark? - Actually checking Operation Fox, en.wikipedia.org/wiki/Invasion_of_Iceland, was as early as 10th May 1940 so any invading force would be opposed by at least the 900+ Royal Marines in the initial invasion if nothing else. 

The Royal Navy and the RAF do also need a large presence there to successfully stop any German landings.

[stevep]

Jul 24, 2017 2:51:54 GMT lordroel said:

Jul 23, 2017 21:12:03 GMT stevep said:

  I suspect the most likely result however would be that the invasion force is likely to be intercepted and possibly suffer heavy losses on the way.  Not to mention is this invasion before or after the island is garrisoned by Britain after the surrender of Denmark? - Actually checking Operation Fox, en.wikipedia.org/wiki/Invasion_of_Iceland, was as early as 10th May 1940 so any invading force would be opposed by at least the 900+ Royal Marines in the initial invasion if nothing else. 

The Royal Navy and the RAF do also need a large presence there to successfully stop any German landings.

  It would depend on the details.  The Germans can't operate any a/c that far out and any naval units can't stay long as they would either run out of fuel/supplies or get hammered by the RN. 

  If the Germans can land enough forces, possibly aided by naval fire support, to drive the marines [plus any other defenders] away from the beaches it depends on whether the defenders are able to withdraw inland in good order and how much damage they inflict on the attackers.  Plus how much of a defence can the Germans put up to the British response, which will definitely be supported by powerful naval support and possibly carrier a/c whereas the Germans can possibly support with subs but that's about all.  Basically its a question of how much the Germans can cost Britain before the islands are liberated.

[lordroel]

Jul 24, 2017 21:41:02 GMT stevep said:

Jul 24, 2017 2:51:54 GMT lordroel said:

The Royal Navy and the RAF do also need a large presence there to successfully stop any German landings.

  It would depend on the details.  The Germans can't operate any a/c that far out and any naval units can't stay long as they would either run out of fuel/supplies or get hammered by the RN. 

  If the Germans can land enough forces, possibly aided by naval fire support, to drive the marines [plus any other defenders] away from the beaches it depends on whether the defenders are able to withdraw inland in good order and how much damage they inflict on the attackers.  Plus how much of a defence can the Germans put up to the British response, which will definitely be supported by powerful naval support and possibly carrier a/c whereas the Germans can possibly support with subs but that's about all.  Basically its a question of how much the Germans can cost Britain before the islands are liberated.

We can agree that due the distance of Iceland and the United Kingdom both the Battle for Britain will not be effected.

[stevep]

Jul 25, 2017 14:46:24 GMT lordroel said:

Jul 24, 2017 21:41:02 GMT stevep said:

  It would depend on the details.  The Germans can't operate any a/c that far out and any naval units can't stay long as they would either run out of fuel/supplies or get hammered by the RN. 

  If the Germans can land enough forces, possibly aided by naval fire support, to drive the marines [plus any other defenders] away from the beaches it depends on whether the defenders are able to withdraw inland in good order and how much damage they inflict on the attackers.  Plus how much of a defence can the Germans put up to the British response, which will definitely be supported by powerful naval support and possibly carrier a/c whereas the Germans can possibly support with subs but that's about all.  Basically its a question of how much the Germans can cost Britain before the islands are liberated.

We can agree that due the distance of Iceland and the United Kingdom both the Battle for Britain will not be effected.

  I can't see it really affecting anything in the BoB.  There will be land and naval units involved but not the land based air units that will be fighting over Britain.  It will draw some naval units north but since the Germans were never really in a position to invade I don't think that would have any real impact.  If the KM lost some more of its few remaining surface units that could impact on morale and its raiding abilities.  Conversely possibly if a sub takes out a big British ship that could have longer term impacts but nothing likely to influence anything in 1940 at least.