Our date with destiny is at hand.
It looks increasingly likely that an agreement on the revised terms of the UK's membership of the EU will be reached later this week with the other member states. If so, the British people will most likely be voting on our membership later this year.
Like many in our country I feel torn over this issue. I am an admirer of David Cameron. He is a strong leader. He is a patriot. He has an enormous intellect which he allies with sound judgement and a cool temperament. Whatever happens in this referendum, I want him to stay on as PM. (Truth be told, I rather wish he hadn't committed to standing down at all).
And I also agree with him that leaving the EU would not be easy. It carries risks. There could be a run on sterling. Renegotiating trade deals could be tortuous and uncertain. Ditching the European Arrest Warrant could delay and even impede justice. Our United Kingdom itself could be imperilled.
So as a gradualist, albeit a eurosceptic one, I am instinctively drawn to a strategy of recalibrating our relationship with Europe, repatriating certain powers, without causing a permanent rupture.
But the conflagration in the Middle East, and our ability to manage the migration pressures whilst remaining in the EU, has shifted the dial in my thinking.
Let me be clear: we need immigration. Our nation was built on it, and new arrivals continue to add immeasurably to our economy and the richness of our culture. But there must be limits. When immigration is too high, when the pace of change is too fast, the cohesion of society can be put at risk. It is difficult for schools and hospitals and core infrastructure like housing and transport to cope. Precious green space comes under pressure.
Annual net migration to the UK for the year ending June 2015 was over 330,000. And now, under EU free movement rules, the million people admitted to Germany could in due course move to live in the UK. Of course not all of them would, or even most. But what if just 200,000 did? How would we cope?
And what if this is just the beginning? What if Iraq collapses? Or Libya?
There is still some way to go, and I won't be rushed into making my decision. I respect the Prime Minister and will listen to him carefully.
But the scales are starting to shift.