There were NO concepts of nation states or tunisia during ottoman times or for that matter anytime in Islamic or pre-17 century European history. Nationalism is a modern form of tribalism. Arabs fought alongside turks throughout 18th and 19th century. Its blatant western influenced ehtno-Nationalism and turkification that formented discontent among Arabs and other ethnicities in the then ottoman empire.
You may love your town,city,province,country you were born or raised in. Its natural to feel a belonging to it. But problem arise when that abstract notion is turned into nationalistic zeal whereby any and all sorts of injustice of your group can be "justified". Its the same as pre-islamic tribalism that Islam condemns - that zeal whereby your conscious and morals are clouded.
nationalism helps forment supeirority complex, ego & false pride something that does NOT behoove the son of Adam since this superiority complex, ego and flase pride is a feature of saytan Iblis. Example - If tunisian goverment or majority in society commits or supports a wrong, you as a Muslim should NOT follow their lead but oppose them and stand up for justice. That's what it means to be a Muslim (assuming you are a muslim) opposing nationalism.
Note- sorry for the long post irrelevant to this thread. I hope you do NOT take it in a negative light or mistake it as a rude condescending post. I only had good intentions behind my post.