Hi bentdi -
Or you could buy a hiking trekking pole transit bag and check that in. Available I believe from that nice Mr Amazon chap, who seems to give you options. Then check that in and retain your carry on bag, even if it’s only for the European and homeward leg having got a pair of Lidl (other brands are available!) poles once in Europe. I realise that it kind of detracts from the smooth, non-stick carry on experience, but it is one way round it without raising the ire of TSA and/or the European Airport Security Agents, who I believe follow exactly the same line re poles.
And…. I don’t know which airlines you are travelling with in Europe but check your carry on fits with each airline’s requirements. Ryanair only allows you something the size of a knotted handkerchief as carry on in comparison to the ‘state’ airlines and they will charge you a swingeing fee if you haven’t pre booked a check in bag online in advance - it’s why they are not well liked in general. Same goes for the likes of EasyJet and Wizz, for instance, although they aren’t quite as blatant. If you end up having to check in your bag anyway it makes the poles query redundant!
Have a great trip!
Ian