'Modernity typically refers to a post-traditional, post-medieval historical period, one marked by the move from feudalism (or agrarianism) toward capitalism, industrialization, secularization, rationalization, the nation-state and its constituent institutions and forms of surveillance.' (Wikipedia, http://en.wikipedia.org/wiki/Modernity, Accessed on Friday January 10th 2014)
The two most important aspects of Modernity are described by the terms 'comparative' and 'unavoidable'. A traditional society that chooses to abstain from the challenge of modernisation puts itself into a disadvantageous position and risks becoming obsolete as well as losing its sovereignty. With the sole exception of geographically isolated indigenous communities, every nation-state is obligated to follow the way of progress, in order to prolong its economic and military prowess and preserve or advance its position in the international system. Otherwise, its neighbours - whether allies, neutral or antagonists - will exploit the 'window of opportunity' to strengthen themselves. As Greek historian Thucydides put it: 'The strong do what they can and the weak suffer what they must' ('Thucydides and the Ancient Simplicity: The Limits of Political Realism', Gregory Crane, Pg 27, Google Books http://books.google.gr/books?id=duh8LPd1-E4C&pg=PA27&lpg=PA27&dq=thucydides+the+strong+do+what+they+...).
Since Modernity is associated mostly with technology and intellectual openess, which in turn translate into patterns of economic activity and institutionalization/political participation, it is obvious that religious fundamentalism and undemocratic background hinder that goal. Modernity combines the organizational structure and resources of the state with the intuition, imagination and initiative of the individual. Thus a certain degree of personal freedom in economic, social and political activities is considered vital.
As far as the Islamic Republic of Iran is concerned, the basic challenges that it faced from the 19th century onwards revolved around having a central government with the ability to collect taxes, maintain regular army and control its borders. In other words, proving itself a sovereign nation-state against both external and internal threats. Caught in the geopolitical struggle between the Russian and the British Empires (known as the 'Great Game'), Iran managed to avoid colonization but nevertheless lost the de facto control of its northern and western provinces. Foreign interference, under various pretexes, continued till the first half of the 20th century. Iran was important not only as a passage/supply route to Central Asia (the so-called 'Persian Corridor') but also as an oil exporter.
In retrospect, Iran's case is unique. Despite sharing the same turbulent past as the rest of the Middle East, with civil wars / regional conflicts / coups d'état, it didn't experience colonial governmental assimilation and therefore it didn't inherit, imitate or adopt the western...