Fantastic news for Brazilians because Russia isn't part of Europe.
European teams usually play the best on a European continent, due to a familiar climate and on European WCs, usually 6 quarterfinalists are lately from Europe.
On the other hand, when WCs are played in South America, Asia or Africa, European teams usually play horrible and are not used to a different climate (since 99% of players from European NT have played their whole career only in European countries).
Brasilian and Argentinian players are both used to play both in South America and in Europe.
But still, in short:
When a WC is in South America/Asia/Africa: Brasil and Argentina will usually have only 1-2 European opponents who will be able to overcome climate problems.
But when a WC is in Europe, Brasil and Argentina will have 5-6-7-8-9-10 strong European teams as opponents who will play at 100% (usually: Italy, Germany, Spain, France, England, Portugal, Netherlands, Croatia, Belgium) and they can get knocked out by any of them.
So, when a WC is in SA/Asia/Africa, a winner will be: Brasil/Argentina or 1-2 European teams
When a WC is in Europe, a winner will be: Brasil/Argentina or 5-6 European powerhouses plus, 3-4 European teams can cause huge problems (Netherlands, Belgium, Croatia, Denmark etc).
Stats:
Quarterfinals:
2014, Brasil:
European teams (4): France, Germany, Netherlands, Belgium
Non-European (4): Brasil, Argentina, Colombia, Costarica
2010, South Africa:
European (3): Netherlands, Germany, Spain
Non-European (5): Brazil, Uruguay, Ghana, Argentina, Paraguay
2006, Germany, European soil:
European (6): Germany, Italy, Ukraine, England, Portugal, France
Non-European (2): Brazil, Argentina (lol)
2002, Korea&Japan:
European (4): Germany, Spain, England, Turkey
Non-European (4): Brazil, South Korea, USA, Senegal
1998, France, European soil:
European (6): Italy, France, Germany, Croatia, Netherlands, Denmark
Non-European (2): Brazil&Argentina
1990, Italy, European soil:
European (6): Germany, England, Italy, Yugoslavia, Ireland, Czech
Non-European (2): Argentina, Cameroon
So, last 3 world cups in Europe:
Quarterfinals were: 6:2, 6:2 and 6:2 for European teams. With non european teams in quarters: Brasil, Brasil, Argentina, Argentina, Argentina and Cameroon.
While, last 3 World cups outside Europe:
European vs Non-European quarterfinalists: 4:4, 3:5, 4:4
When playing outside of Europe, lots of European teams are all over the place.
They can't cope physically on other continents and they often play like a total garbage.
While, again, on European soil, at least 10 European teams can knock out Brasil and Argentina in any match of KO rounds.