1. THE INTERNATIONAL
LAWS OF WAR

2. The “Just War” tradition
was developed in
medieval Europe.
Its theorists were thinking
about this sort of war:

3. ...rather than this
sort of war:

4. In fact, its origins go
back as far as the
writings of some
ancient Greeks and
Romans.
This kind of war:

5. One of the most famous
theorists of “just war” was
Hugo Grotius.
He was a jurist from
Holland, born in 1583.
This is his picture:

6. Grotius lived to see two
horrible wars - the Eighty
Years War between
Holland and Spain, and
the Thirty Years War
between Catholic and
Protestant nations in
Europe.
(This is a painting from the Thirty
Years’ War is called the Miseries of
War.)

7. This made him want to
write this book about war
and religion -
(“De jure belli ac pacis” means “On
the law of war and peace”)
The basic argument was
that some wars are
justifiable.

8. The idea of a just war
was heavily influenced
by the codes of chivalry -
Think knights in shining
armour, behaving
honourably, protecting
vulnerable damsels in
distress and so on...

9. The ideas about the justice of war are divided into three
parts:

10. 1.
jus ad bellum
ideas are about the circumstances under which it’s ok to
go to war

11. Jus ad bellum rules are
aimed at the people who
can make that decision -
heads of state.
Back when Hugo Grotius
was writing, that might
have meant King Louis
XIII of France, known as
“the Just”:

12. More recently, jus ad bellum
principles are speaking to
people like this rather
more familiar character:
George W Bush, was President of the
USA and “commander in chief” when
the US went to war against Iraq.

13. 2. Jus in bello ideas describe
the sort of behaviour that
is justifiable during a war

14. 3. Jus post bellum talks
about the proper way to
go about ending a war, for
example, in drawing up
peace treaties.

15. The principles of “Just War”
are not independently legal.
Still, they are fundamental
to the modern laws on the
use of force.
“Jus ad bellum” and “Jus in
bello” continue to be the
ways we categorise war law.
(A famous example of “Jus
in bello” are the rules of the
Geneva Convention.)

16. This course is about the legality of going to war - that is,
the “jus ad bellum” side to law.
The way we - and our military
and civilian leaders, and the
lawyers who frame our
international laws - think
about war has changed.
Crucially, after the horrors of
WWI, the western leaders
decided that war was, as a
rule, a bad idea.

17. So, in 1928, the Kellogg-
Briand Pact outlawed war.
It remains a binding treaty Not this guy:
for all the 63 states which
signed it into existence.
That’s this guy:

18. A bit later on, I’ll return to
the failure of the Kellogg
Briand Pact and what
came after.
Meantime, its time for
level 2!