Australia takes its international responsibilities very seriously The reasons behind the rise of Islamic State are complex.
Mike Reddy's reply (Letters,   November 17) to to A.Pavelic (Letters,   November 19) accuses him of something he did not say (closing borders) and, somewhat ironically, of "one-eyed" and "short- memory" barracking.
That was followed by a syllogistic and largely linear claim of cause to effect that Australia "played a major role in the rise of [the so-called] Islamic State" to 2014 by joining the 2003 intervention in Iraq. 
In a complex geo-political situation, other factors surely played predominant roles over this decade.
First, the Shiite sectarianism and general corruption and incompetence of Iraq's Maliki government once free elections had been enabled, international forces had left over 2009-11 and there were few external or internal restraints on Nouri al-Maliki's counterproductive actions.
Second, the Arab Spring and particularly its resonance in authoritarian Syria, where the supposedly malign "Western" influences to which Mike attributes continual blame have been almost totally absent, and no actual military interventions have occurred, since the final French withdrawal in 1946.
Finally, the ideological or other simplistic belief that countries contributing to multinational stability and peacekeeping operations in overseas trouble spots incur some kind of additional responsibility for refugees fleeing such locations surely turns morality, logic and the UN charter on their heads.
Instead, it is the countries that avoid helping UN and other multinational efforts to ameliorate or resolve crises at source so refugees can safely return home that are usually the same humanitarian bludgers who refuse to sign the Refugee Convention, or only pay lip service to its obligations, even for crises in contiguous countries.
For all our occasional faults in execution, and especially in contrast to virtually all our neighbours, Australia rightly takes both types of international obligation seriously.
Neil James, executive director, Australia Defence Association Churchill's example So, Dr Marjorie Curtis (Letters,   November 20) laments the absence of Winston Churchill to lead the response to the terrorist atrocity perpetrated in Paris.
Would this be the same Winston Churchill who was secretary of state for war when both Sunni and Shiite communities in Iraq revolted against British rule in 1920, in the first "Arab Spring", and who directed its ruthless suppression?
The same heroic Winston Churchill who advocated the use of chemical weapons "against recalcitrant Arabs as an experiment", adding "I am strongly in favour of using poisoned gas against uncivilised tribes to spread a lively terror" in Iraq?
John Richardson, Wallagoot, NSW Violence and Islam H.Ronald (Letters,   November 18) had hoped the Grand Mufti would have denounced the attacks in Paris as "an affront to Islam". Obviously, the Grand Mufti is aware - as we should be - that violence and Islam are not uneasy bedfellows. History reveals that during the seventh and eighth centuries AD, Islamic warriors subdued about half of the Christian population by violent means, and killed many non-Muslims over the centuries that followed.
We must keep in mind that ultimately the subordination of all people to Muslim rule is the objective that lies at the heart of traditional Islam. One way to achieve that goal is through violent jihad. Koran 2:216 advises: "Fighting is obligatory for you, much as you dislike it", while 9:123 tells Muslims: "Believers, make war on the infidels who dwell around you".
While Paris is on many minds, may I draw readers' attention to the church-burning that has taken place recently in Aceh apparently with the approval of the authorities. Did Mr Turnbull allude to that barbarity when he met Indonesia's President, Joko Widodo, recently?
Henk Verhoeven, Beacon Hill, NSW Decision baffling For someone who has spent close to 40 years teaching and doing research at the university, I confess to being baffled by the Turnbull government's decision to reduce the funding to those universities that allow their research- active staff to publish their findings in academic journals ("University watchdog puts 'gamers' on notice"   November 18, p6).
It makes one ask who is advising the government on this matter?
Surely, these advisers must be aware that before one's research output is accepted for publication, it has to be scrutinised thoroughly, for quality and authenticity, by academic peers.
So, who on earth is going to take notice of our publications, even if they were to reveal new findings, if they do not appear in one of the popular international academic journals, to which most of the libraries subscribe.
Sam Nona, Burradoo, NSW Work already done My thanks to Mike Dallwitz (Letters,   November 19) for suggesting I undertake a quantitative analysis of the impacts of an increase in the rate of GST.
Thankfully, Ben Phillips and Matt Taylor from the National Centre for Social and Economic Modelling at the University of Canberra have done that for us.
Relying heavily on Australian Bureau of Statistics household expenditure data, modified for the purposes of their analysis, they conclude that an increase in the GST rate and expanding its base to include fresh food, health, education and financial services would hit the poor and less well paid more than the rich. Rich people spend more overseas, on holidays for example.
But there is more to it than that. As Phillips and Taylor say: "Low-income households tend to spend proportionately more on necessities, such as food and petrol. Of particular importance is the reality that higher-income households, on average, save some of their income, while low-income households spend more than their income. This has important implications for the regressivity of the GST with respect to income."Their paper, "The distributional impact of the GST" (  November 2015) is available online. It is well worth the read.
John Passant, Kambah