Junction means (1) the act or process of joining, (2) a place where two things join or meet, and (3) a layer or boundary between two different things. Juncture means, primarily, a point in time made critical by a concurrence of circumstances. Juncture was traditionally a variant of junction, but the words had completely differentiated by the 19th century.
Examples
The phrase at this juncture is often used as a fancy way of saying at this time or now. For example, these sentences use at this juncture to describe a point in time that is not particularly critical:
What made him go there at this juncture in his life, 31/2 decades after the Band packed it in? [Los Angeles Times]
Rivers, a 6-foot-3 guard headed to Duke, put on the best show, draining seven straight 3-pointers at one juncture and making several great passes. [Chicago Tribune]
And these writers use juncture well:
At this juncture, Ivorians need a healer as much as the country needs visionary leadership. [Daily Beast]
It is at this juncture that we have to be very careful with any suggestion of decriminalisation. [Telegraph]
And these writers use thee more straightforward junction well:
Our plan is to allow them to set up a small checkpoint at a road junction in one of the villages. [National Post]
It’s the deadliest road junction in the Far North but there is still no sign of safety improvements flagged years ago. [Stuff.co.nz]

