From the article: 'cases of young Muslim men living in Germany becoming jihadi combatants are rare [how rare is 'rare'? - CM] but increasing in number.

[They are increasing in number because the Ummah in Germany is getting bigger and therefore is - and feels itself to be - more powerful. The more Muslims you have anywhere, the more jihad plotters and sharia-pushers you will have. - CM].

'German security services believe that since the beginning of the 1990s [that is, in the past 20 years - CM] around 235 people [that's about ten per year - CM] "with German connections and Islamic terrorist backgrounds" have at least attempted to obtain paramilitary training.  There is concrete evidence that around 100 were actually trained or engaged in military operations.

'More than half of these are said to be back in Germany'. [Why are they back in Germany at all? If they were known to have gone in search of jihad and/ or jihad training, if there is reasonable suspicion that they had done so, then the precautionary principle should have been applied: they should not have been permitted to return to Germany or indeed into the EU or any other non-Muslim land,  and their German residency, or their German citizenship, should have been cancelled. -CM] and around 10 have been imprisoned. [Why not, 'stripped of residency and/ or citizenship, and deported to their country of birth or of ancestry? - CM].

AND 'you need a clever form of prevention'.

Here are a few ideas.

1/ STOP all further entry of Muslims into Germany.  Muslims simply should not be allowed to enter Germany: not as 'asylum seekers' or 'refugees', not as 'immigrants', not as 'students', not as 'tourists', NOTHING.  Keep them out.  

This would somewhat slow down the expansion of the Ummah.

2/ REMOVE from Germany all Muslims - such as Mounir and Yassin C, the Moroccan Muslims currently resident in Germany - who are busy fomenting jihad and/ or pushing sharia.  REMOVE all Muslims caught advocating or practising or attempting to practise all those aspects of sharia (or practices more or less tacitly condoned by sharia) - e.g. wife-beating, child-marriage, forced marriage, polygyny, FGM, 'honor' murder, murder of apostates and 'blasphemers' - that flagrantly violate German morality and law.

 If they are not citizens, if they are present illegally or only have residency, then that should be that: out they go to their country of origin.  

If they have citizenship, their flagrant violation of German law and custom and/ or their encouragement of other Muslims to violate the law, should trigger the nullification of their citizenship.  

This measure would immediately and quite perceptibly reduce the size - and therefore the perceived power - of the Ummah within Germany, and serve notice on them that the free ride is well and truly over.

3/ Offer real protection and help to those who genuinely defect from the Ummah; who have publicly declared their apostasy from Islam, their embrace of Christianity or of the European Enlightenment, or of some other non-Muslim belief system, such as Buddhism.  It should be proclaimed loud and clear that a girl from a Muslim background who wants to a/ leave Islam and b/ marry a non-Muslim, will be welcomed, assisted to find a safe place, and resolutely protected from any pursuing 'hit men'.  

Of course, apostates seeking such help will know, none better, why they  will have to accept some sort of parole or 'probation' system as they enter the non-Muslim world; if they are genuine, they will be only too happy to cooperate, recognising the need for everyone to be protected from the possibility of the Double Agent.

 In conjunction with this, constantly publicise - in languages used by Muslims in Germany, such as Turkish and Kurdish -  intelligent critique of Islam, and the exposition of the benefits of practising a non-Muslim belief system; especially when such critique, and such exposition, is carried out by known ex-Muslims.  Though Fr Zakaria Botros' hard-hitting programs could do with rebroadcasting - dubbed into Turkish and Kurdish.  Flood the airwaves and the internet, with this sort of thing. Greatly magnify the voices of people like Patrick Sookhdeo, Mark Gabriel, Daniel Shayesteh, Magdi Cristiano Allam, Ayaan Hirsi Ali, Wafa Sultan and many, many others.  The jihadis used the internet, especially youtube; well then, overwhelm them!  Produce more, and better, presentations of All The Alternatives to Islam.

Oh, and make sure that native non-Muslim Germans, especially the most vulnerable, are exposed to relentless and thorough, and intelligent, critiques of Islam, especially of its most antihuman - the ban on art, on music, on pet dogs; and its condoning of FGM - and its most ridiculous aspects.  Those who consider converting to Islam should know that if they do they will be a/ regarded with rational suspicion and disgust (precisely as if they had announced their having joined the KKK, or a neonazi group, or the Mafia, or a pedophile ring) and b/ laughed at.

And these measures, too, would bring about an erosion of the Muslim beachhead.

The only way to be quite, quite sure of having no jihadists within Germany is to have no Muslims within Germany. But given that a mass deportation of Muslims is unlikely to take place in the immediate future, each of the options I have outlined might function as interim measures, and would have some benefit.