In the summer of 1942,

the Japanese Empire stretched over a vast area of the western Pacific

After the attack on Pearl Harbor in December 1941,

Japanese forces moved quickly to capture Hong Kong,

Burma,

Malaria,

Borneo, the Philippines,

and Singapore.

By the spring of 1942,

Japanese troops were in New Guinea

as the expanding empire swept into the Solomon Islands,

By the end of May,

Japanese territory spread as far as the large jungle island

that would give its name to one of the best-known episodes of the Pacific War,

Guadalcanal.

Japan's expansion was a seemingly relentless advance.

But around the time they reached Guadalcanal,

the tide was already beginning to turn against the Empire.

The May 1942, Battle of the Coral Sea

forced Japan to shelf(?) the idea of attacking New Guinea's capital.

Port Morseby.

In early June,

the stunning American victory at Midway

persuaded the Japanese leadership

to halt their expansion into the Pacific.

Consolidation was now the order of the day.

But the Empire was still a force to be reckoned with.

In the middle of June 1942,

Allied intelligence in the Solomon Islands

reported a worrying development.

The Japanese occupiers of Guadalcanal

were constructing an airfield on the north coast of the island.

Coconut trees were being felled in the thousands.

and the reports suggested

that the airstrip will be operational in a matter of weeks.

This was serious news for the Allies.

A Japanese air presence on Guadalcanal

would threaten the precious supply line between Hawaii and Australia.

In Washington,

the American chiefs of staff considered their response.

One idea was to carry out a raid against Guadalcanal,

and put the airfield out of commission.

But eventually a plan was hatched

that was far more bold in scope.

Instead of merely raiding Guadalcanal,

the Americans decided to capture the island.

The plan was to effect an amphibious landing by American Marine forces,

eject the small Japanese presence,

and establish an Allied airbase on the island.

By June the 25th,

the decision was made to go ahead with the operation,

its code name

Watchtower.

The Prelude

When the decision was made to capture Guadalcanal,

the American planners knew very little about the background that lay ahead

the island was almost entirely unfamiliar.

Maps were few and unreliable,

and only a limited air reconnaissance was possible.

And this was not the only problem that affected American preparations.

The success of the Guadalcanal offensive

would depend on the Marine troops

whose task was to go ashore

and physically capture the vital airstrip.

But when the Marine commander

General Vandegrift

received his orders at his headquarters in New Zealand on the 25th of June,

he knew that his men were far from combat ready.

It was early in the previous month that the marines

had left their home base in North Carolina.

And by the end of June,

only 1/3 of their number had arrived in New Zealand.

General Vandegrift had been told

not to expect any operational duties until 1943.

Now his unprepared division

was expected to go into battle in a matter of weeks.

Vandegrift was forced into urgent preparations in New Zealand

as his men and supplies arrived in the region.

Despite an outbreak of influenza amongst his troops

and the inconvenience of a strike

amongst the dock workers in the Port of Wellington,

by the end of July

the Marine troops were in position

on the island Fiji

awaiting a final rehearsal for the task ahead.

General Vandegrift by now secured a postponement to the day of attack

from August 1st to August seventh.

But he knew that his preparation time have been far from ideal.

And in Fiji,

the inexperience of the American Marines revealed itself.

The Guadalcanal expedition

would be an amphibious operation

quite unprecedented in size.

And the Fiji exercise

revealed the logistical difficulties involved.

There was little evidence of coordination

between the amphibious landing groups

and the accompanying naval and air support.

Equipment proved unreliable.

And the whole exercise was judged to be a little less than a farce.

But there could be no delay in the timetable.

August the 7th would be the date

when the American plan would be put into action.

The intentions of the American leadership for the Guadalcanal offensive

were relatively straightforward.

An armada of transport ships

would sail from Fiji to the Solomon Islands

and into the channel to the north of Guadalcanal.

There, the main amphibious force

would take to their landing crafts and go ashore

while supporting units

secure the smaller islands of Tulagi,

Gavutu,

and Tanambogo.

The transport vessels would not be alone.

Instead,

they were just part of a much larger invasion force

To the north and northeast,

lay a substantial protective naval presence

under the command of Admiral Crutchley of the Royal Australian Navy.

5 cruises and 9 destroyers

Generous air support was also provided.

Some 100 miles to the south,

An American carrier fleet formed into position.

The value of the aircraft carrier

had already been proved dramatically at the Coral Sea and Midway.

And so the Carriers Saratoga,

Wasp,

and Enterprise were deployed

to provide fighter support for the Guadalcanal offensive.

Alongside the carriers,

one battleship,

6 cruises and some 16 destroyers,

These substantial resources

were all deployed in support of Vandegrift's First Marine Division,

a landing force reinforced

with crack units of paratroops and Marine raiders.

But nothing could hide the fact

that the 1st Marine Division had only been formed recently

and the majority of its men

lacked any experience of battle.

The American Marines could not be sure

of the size of the force that waited them on Guadalcanal.

But they could guess the strength of the Japanese fighting spirit.

The best intelligence available suggested

that the force of 7,000 troops were in position on the island

and these were likely to include soldiers

with recent experience of fighting in difficult jungle conditions.

By contrast,

there were few men in the American Marines

who would ever come across

an environment like that of Guadalcanal.

The Americans also knew that Japanese strength

did not derived only from its positions

at Guadalcanal itself.

Somewhere to the northwest,

in the vicinity of New Britain,

lurked the might of Japanese naval power,

the 4th Inner South Sea Fleet.

These were the concerns that face the American commanders

on the eve of battle in early August 1942.

American Commanders

In overall command of the Watchtower Operation

was Vice Admiral Robert Lee Gormley.

The 57-year-old who had served as a liaison officer in London

Gormley arrived in New Zealand in March 1942

to take up command of the South Pacific area

and South Pacific Force.

Not long afterwards,

he received the order to proceed

with the Guadalcanal attack.

But Gormley would not be in the South Pacific

when the fighting finally ended.

His eventual removal

may have been the result

of one of his decisions in the early days of the offensive.