The present situation in the UK and the US, as well as other places outside the established regions of Orthodox Churches, is rather complicated. The long established local religious communities in these places are heterodox and as such are not in unity with the Catholic Church, that is the Orthodox Churches in communion the Patriarch of Constantinople. Thus, the Orthodox emigrants to the UK or to the US did not have preexisting places of worship nor local hierarchy to establish such places. These had to be provided from their home regions. Sadly, due to lack of coordination between Orthodox Patriarchs, we have the situation of a number of hierarchs establishing churches for immigrants in the UK and the US. This situation has led to a neglect of the territorial definition of churches and to definition along national/ethnic categories, which is contrary to the teaching of Christ. We need to repent of this. It is suggested that the only way forward is to appoint and recognise a local territorially defined hierarchal structure for the UK or US with its own synod, although overseen by one of the present Patriarchs. Also, this hierarchy must attempt to convert the heterodox back to Orthodoxy and allow the local peoples to take ownership of the church within their own territory.
The use of vestments could be helpful to distinguish the hierarchy of the UK or the US from the hierarchies elsewhere. This is not in order to separate them but to highlight that the churches in the UK and the US are not part of other national churches, although most members within the churches in the UK and the US may be descended from these other nations. The churches in the UK and US should be seen as local churches in their own right. A distinction of vestments helps to provide visual recognition of this local hierarchy and to break it from being considered part of a nationally defined group. Yet, in terms of being orthodox, the vestments need to be consistent with the traditional form of vestments used through the history of the Church.
To enable the choice of vestments, even though most religious groups in the UK and the US are heterodox, some of their heritage comes from an orthodox background and maintains orthodox standards manifested in the cultural context of the UK and the US. It would be wise for the orthodox hierarchy not to impose an exterior manner of dress upon the UK and the US but rather to take what is already within that region consistent with Orthodox Tradition and establish it for use of orthodox Christians in that region. This would allow the local peoples to have greater identity and ownership of the church in their territory, rather than the church arriving as a foreign institution imposing its own national cultures as well as bringing orthodox Tradition. While it is important that each region or nation is established in the international community and participates in customs that are required for relationships across this international community, otherwise the local community becomes isolated and estranged, at the same time each region or nation should participate without losing the diversity of its own customs, where these do not go contrary to the international community. In orthodox terms the common customs of the international community are given in Holy Tradition, which is the common way of life in Christ as Christ that unites us with Christ, yet the regional customs are maintained that of self-rule in synergy with Christ as maintaining God’s image as man with the ability to govern. This governance is expressed in the diversity of customs within Tradition. For one national church to impose in entirety of its customs on another nation is to undermine and deny the self-rule of that nation thus denying the image of God in its people and the synergy of the relationship of God and man in deification.
Unfortunately, we are well beyond the point where distinctive vestments will make much difference. The Orthodox Western Rite is one attempt at a way forward, but has been problematic so far. We are a long, long way down the road from the pre-schism Church in the West. It is probably futile to try and fumble our way back at this point.
The root of the problem is that the UK and US no longer really have a national ethnic identity or traditional customs to offer a missionary Church. To the extent any vestigial expressions of ethnic identity and culture remain, they are condemned and actively deconstructed as racist relics. This is hardly just the fault of the immigrants. They are what they are, and there is much not to like of modern, heterodox Anglo culture. It can also be said that this is the Anglo's universalist, protestant creed coming back to bite them. Having abandoned local, organic culture for globalism and universal democracy, the Anglo's cannot now be heard to complain when the rest of the world takes them up on their offers. A dysfunctional people who can't reproduce themselves will be replaced.
Thus, the UK and US now find themselves as headquarters of global trade and finance even as their founding stock are increasingly strangers in their own lands. The adaptive strategy of their intelligentsia has been to embrace this highly mobile, progressivist worldview and they are doing extremely well by it; their less-talented countrymen, not so much.
Historically, the autocephalous Churches evolved from their missionary status to national institutions wedded to their cultures through an inter-generational procession of grandparents, parents, children and extended family with no conception of the Church as anything but Orthodox faith and praxis. A country of present-centered nuclear families (and single moms) where "church" is just a matter of denominational preference is awfully thin soil. (Matthew 13:5-6).
There is no Divine mandate by which the Church will be established at any particular place. If the Anglosphere (or the Middle East) ultimately rejects the Church, she will shake the dust off her feet and depart, and God will judge. (Matthew 10:13-15).
P.S. The linked thread includes a very interesting comment about immigration from an Athonite monk, Patrick. National identity is weighing on a lot of people's minds in a lot of different spheres these days.
Monk Patrick's biography:
A hierodeacon of the Orthodox Church in New Zealand (Ecumenical Patriarchate) presently living on Mt Athos gaining some experience living the theology of Sts. Maximus the Confessor and St Gregory Palamas before returning to serve in New Zealand. Also, presently completing a Master’s degree in Theology (Orthodox Studies) at the University of Wales (Lampeter) with Dr Andreas Andreopoulos, who previously studied with Fr Andrew Louth. A member of the Institute of Orthodox Christian Studies in Cambridge, England and spiritual child of Metropolitan Kallistos Ware. Previous academic qualifications are degrees in Mathematics and Law from New Zealand. A convert in 1996 from an evangelical protestant background with earlier experience in charismatic/pentecostal churches.