There are at least three ways you could look at the significance of this event. The first is at a personal level, for that you need to have your own natal chart and look to see where these three planets are placed, their general condition and which houses they rule. The significance might range from almost nothing to very significant, depending on those factors. It's more likely to be at the significant to very significant end because you have three major planets involved but the 'where and how' of the significance depends on their role in your chart and the house(s) they are placed in by transit. Currently all three planets are in Virgo, so what you need to look at is what house(s) contain Virgo in your chart - they will receive the most effect, any house(s) involving Pisces (opposition), Capricorn and Taurus (Trines), Gemini and Sagittarius (Squares) or Scorpio or Cancer (Sextiles) will have some effect, especially if they contain a planet near to the degree of the three (14 degrees for the Jupiter Mars conjunction).
The second way you could look at is at national level or even city level, if there is a chart for your country or city. That will give you some idea of the general impact locally. The procedure is the same as above but bear in mind that what befalls your country is not felt in equal measure by all who live there, some may be strongly affected, other may not. This isn't personal it's national.
The final way you could look at it is as an omen for the world, and that becomes extremely general. Here you have the symbol of good fortune, in a weak state (Jupiter is in detriment) being afflicted by the lesser malefic (Mars) a symbol of loss, usually be severance. But there is help coming in the shape of Venus (the lesser benefic) who happens to be a triplicity lord in Virgo. So whatever evil comes from the struggle of Jupiter and Mars, will be mitigated or even cancelled out by her intervention. The latter is the more likely because Mars and Jupiter are not only in her triplicity they are also in the Bounds of Venus and the Decan of Venus. That is Venus is very powerful in that area of Virgo and she is now applying to both the other two by conjunction.
One of the problems that beginners encounter is that Astrology assigns many different but related symbolisms to planets - they are mult-faceted. Thus Jupiter can mean good fortune, but also faith, higher knowledge, business and commerce, law and the legal system, brotherhood and finding agreement amongst people and joy and a feeling of balance and harmony. Those are not all the meanings but they give you a flavour. If you think about them you'll see that they are all required for a civilised life. Jupiter is symbolic of a civilised society living in harmony.
Mars is more aggressive, combative, and can symbolise fighting, adultery, exile and estrangement from family friends and country, severance and cutting. Vettius Valens says that Mars in general symbolises masculinity but a reading of the list suggests that it's excessive masculinity, a need to assert oneself against the outside world. So one possible interpretation, out of many, and an extreme one could be an act of violence against civilised society or simply forces that undermine civilised society.
Venus symbolises love and yearning (at a general level) and taking care of others. Venus rules the Arts and cultural activities - that which brings us together; what we might call the finer things in life. Thus one interpretation of all three planets is that attempts to challenge the order of things may fail because of the need to maintain our cultural life and to take care of our fellow beings. But I stress that's only one possible meaning and as a global force it's not going to be felt equally in every areas of the world. It might be strong in one region but weak or barely noticeable in another. Nor does it have to be one moment in time but a trend that occurs over a period of time.
